I'm looking for a cheap way to control my simple projects. I have a few things that only require 3 pwm pins (for rgb leds) and some effect processing. The most processing intense thing it would be doing is audio analysis and beat detection. I don't want to use any of my duemilanoves because its over kill and they're expensive. I could use the pro mini but I'm wondering if theres a pre made solution (i.e. doesn't require much assembly and isn't too hard to program thats even cheaper than the pro mini. I found a pro mini for 12.80 on ebay which isn't bad but something in the 5-10 dollar range would be awesome. Any ideas?
Search the threads for "Very small arduino", then PM me for a board 
$2 PCB, $4 uC, couple caps & resistor for pennies, xtal for 31 cents. Square posts as needed for your connections.
Pm sent. Thanks! I'm sure ill be able to figure out how to program it. Oh and i forgot to ask. Do you take paypal? That's pretty much the only way I can pay for stuff on the internet
There's also the 8 pin ATTiny45 or 85 chips that are around $3. For "blinking LEDs" they're great, but not so much if you've got headier processing to do.
http://hlt.media.mit.edu/wiki/pmwiki.php?n=Main.ArduinoATtiny4585
The "blinkm" is designed around this idea.
ATMega328P-AU is just 40 cents more, for way more capability.
I bought a tray (?) of 20 for under $3 each at the time, thinking I'd fix a couple of busted promini's I have.
556-ATMEGA328P-AU 25: $2.97 Tray
Sweet.
556-ATTINY85-20PU 1: $1.62
Even sweeter for those of us who consume too much caffeine to do surface mounting. 
Too much caffeine - We'll see how that works out 8)
I usually have my wife place the small stuff, better eyes than me
TI MSP430 - $4.30. Complete board.
CrossRoads:
Too much caffeine - We'll see how that works out 8)
I usually have my wife place the small stuff, better eyes than me
You fence with that eyesight? 
Yeah, but my opponents are't 0.5mm targets!
TI MSP430
I looked thru their brochure.
To get 32K Flash, 2K RAM, 0 EEPROM, 1 UART OR SPI OR I2C (not 1 of each), so overall less functionality than a '328, you have to go all the way up to MSP430F2370,
which at 1000 lot prices is $2.55, so I can imagine 1-lot will be higher,
and it comes in a handy Ball Grid Array, or 40-pin QFN (leadless) package. Not real handy for DIYers.
Think I'll stick with ATMega's for now.
http://www.nkcelectronics.com/arduino-runtime-board-rev-b.html: $1.99
http://www.mouser.com/ProductDetail/Atmel/ATMEGA328P-PU/?qs=sGAEpiMZZMtVoztFdqDXO6rEZqxeooRg: $3.50
Other parts required on board: roughly $5
[note: fixed link to point to correct part]
This gives you a nice runtime platform for < $10 USD. (Note: the NKC board is NOT shield compatible. I don't typically use shields, so it's not a big deal for me; YMMV)
Take a look at the ATTiny chips as well, especially with Coding Badly's arduino IDE support. Tiny85s are $1.30 each in quantities of 25 on mouser. You can do a lot with these little guys.
http://www.mouser.com/ProductDetail/Atmel/ATMEGA328-PU/?qs=sGAEpiMZZMuHCAZ7U3Ea2vH90mYkP45F
That appears to be the 328 non P version recently discussed in some posts recently. It has different signature bytes then the 328p chip and can fail when burning bootloaders via avrdude when using hardware programmers, unless one does some hoop jumping with text file editing. It can be made to work as posts have shown, but probably not worth the hassle if one can get the p chips to begin with.
Lefty
CrossRoads:
TI MSP430
I looked thru their brochure.
To get 32K Flash, 2K RAM, 0 EEPROM, 1 UART OR SPI OR I2C (not 1 of each), so overall less functionality than a '328, you have to go all the way up to MSP430F2370,
which at 1000 lot prices is $2.55, so I can imagine 1-lot will be higher,
and it comes in a handy Ball Grid Array, or 40-pin QFN (leadless) package. Not real handy for DIYers.Think I'll stick with ATMega's for now.
I think he was referring to the '430 "launchpad" board: Ordering FAQs | TI.com; $4.30 with 2 MCUs. Could be a cheap controller for a one-off project. You're right though, it ain't an AVR. The 430s claim to fame is it's tiny power consumption. It doesn't do a whole lot, but it doesn't use much power doing it...
retrolefty:
That appears to be the 328 non P version recently discussed in some posts recently. It has different signature bytes then the 328p chip and can fail when burning bootloaders via avrdude when using hardware programmers, unless one does some hoop jumping with text file editing. It can be made to work as posts have shown, but probably not worth the hassle if one can get the p chips to begin with.
Hmm, haven't noticed any problems with it, but I'm programming it directly with the STK500.
Works on my machine...
Ugh. Shouldn't post tired. Here's the link to the part I'm actually using:
http://www.mouser.com/ProductDetail/Atmel/ATMEGA328P-PU/?qs=sGAEpiMZZMtVoztFdqDXO6rEZqxeooRg
Good catch, Lefty.
Good catch, Lefty.
It's kind of a strange situation, the p version is the more 'advanced' device because of the pico low power specifications but was released to the public well before there was a non-p version avalible. When the arduino boards first started using the 328 chip it was only avalible as a 328p, there was no such chip as a "non-p" version. Then later AVR came out with the non-p version, so now we have this stumbling block to try and avoid if possible. It only shows up when ISP programming the chip where the signature bytes are read from the chip and compaired to the chip you selected to be programed. It's been an interesting topic as people explained the chip programming process.
Lefty
For while, Atmel had the cheapest microcontroller in the ATtiny11, which they were selling for $0.25 in relatively small quantities. They were not very capable things, and required a special programmer ("High Voltage Serial Programming.") This was apparently a temporary thing while Atmel emptied the supply chain of this particular part 
Currently, the "cheapest micro" spot (for small quantities of reasonably hobbyist-friendly parts) is shared by some of the low-end freescale chips (MC9RS08 series) and low-end Microchip PICs (PIC10F and PIC12F chips), all between $0.45 and $0.70 or so. THe freescale parts seems to shine above the others in areas like code space (2k!) There are quiet a few possibilities for less than $1, including some of Atmels 8051 chips with substantially more pins than most of the other choices.
It all gets a bit meaningless. Going from a $4 chip to a $2 chip is one thing, but below $2 you need to start thinking that the micro is no longer the bottleneck in your design.
None of those are likely to be capable of much in the way of arduino compatibility. If that's what you're looking for, finding a cheap ATmega8 (on eBay they're getting under $2 in 25 quantity. Quality somewhat suspicious.) and an existing blank board to put it on (like the NKC "runtime" board, or a MDC "Really Bare Bones Board", and start thinking hard about what components can be left out and still have your project succeed...
Wow there a lot of good info to sort through thanks guys. I've been looking at the launchpad and a few other boards in that series and I like it. The price on the launchpad is unbeatable and it should work fine for my purposes. One thing though, does anyone know if it has built in own pins and if so how many? If it didn't have 3 I would have to do some tricky code stuff that was much more interupt based but I could probably make it work. The msp430 line looks like its coming along very nicely and are definitely aimed at the same market as the arduino but so far the support is not even close to what arduino has. But then again at 4.30 who even cares haha
The 14-pin CPU on the original launchpad can only do ONE pin worth of hardware based PWM. They may have started shipping the LP with one of the 20pin chips as well; I haven't looked at it...
Ok that's better than nothing, I can probably figure out software pwm while still doing all of my audio processing and stuff based off of interupts