Hi, I'm new to Arduino, but I have lots of experience with programming and some experience with basic circuitry (built a SAP-1!).
My girlfriend wants one of those light-up hula hoops with the different LED patterns, only problem is they are about 250 dollars; so I suggested we could start a project together to make one ourselves.
We want to do a 40 inch diameter hula hoop so we need about 3 meters of lights to go all the way through the tubing, and at 32 lights a meter I am hoping to have 96 programmable lights.
Seems OK for your project. Any other type will do, as long as they have indvidually addressable LEDs. You can even buy indivdual "dot"s, but I think the strip will be cheaper.
CjKen:
What kind of board do should I use, I was thinking an arduino micro or nano (so it fits in the tube)
It really does not matter. The library Adafruit supplies, can be set to use any pins, but the SPI interface is best/fastest, so check the board has the SPI pins (pin 10, 11, 12)
CjKen:
How should I power the board and lights, I was thinking rechargeable AA batteries in series inside the tube (not sure how to recharge them though)
That is the trickiest bit on this project. Whatever you can fit in the tube The amount of current needed for so many LEDs is astoundingly large. If your program keep the LEDs relativly dim then you will not need as large a current as the LEDs otherwise specify. (If you do, the battery voltage drops, as it can only supply a limited current, and your microcontroller resets and nothing seems to work...) it will run longer. On the adafruit page, I followed the links, and it gave good advice on battery capacity. To charge, remove batteries and use an external charger. Otherwise it gets complicated with a charger circuit (Google and you shall find )
CjKen:
How can I place the board inside the tubing (which is 1 inch thick, 2.54 cm)
If it fits, insert it. If it doesn't fit - find a smaller board. LIke http://shop.moderndevice.com/products/rbbb-kit Once the chip is programmed you might make your own bareboard. (I do not see how "place inside hoop" can be a problem)
CjKen:
How can I connect the board to the light strip to control the lights turning on and off (pretty sure I can figure this one out though)
CjKen:
We want to do a 40 inch diameter hula hoop so we need about 3 meters of lights to go all the way through the tubing, and at 32 lights a meter I am hoping to have 96 programmable lights.
Calculate the worst possible usage, all 96 at full 100% white:
96 RGB LEDs = 96 x 3 = 288 channels.
288 channels at 20mA = 5760mA
Even if you only light up one single channel on all of them, that's 96 x 20mA = 1920mA.
A single AA battery can produce upwards of 2000mA (really depends on brand.) So you're going to need to find a different type of battery to run all 96 with. There is a reason why those hoops you see advertised only have a low number of LEDs in them.
The amount of current needed for so many LEDs is astoundingly large. If your program keep the LEDs relativly dim then you will not need as large a current as the LEDs otherwise specify. (If you do, the battery voltage drops, as it can only supply a limited current, and your microcontroller resets and nothing seems to work...) it will run longer. On the adafruit page, I followed the links, and it gave good advice on battery capacity. To charge, remove batteries and use an external charger. Otherwise it gets complicated with a charger circuit (Google and you shall find 
)