Hi guys!
I don't know if this is the right place for suggestions for the development team.
I think it would be definitively nice to allow people to choose the kind of processor on the board. Let's be onest... last day I ran out of memory on my Arduino Diecimila. Despite my optimizations 14kb were not enough and so now I'm back starting from scratch at choosing another development kit.
The problem is that I'm a newbie at embedded development and this is a problem. So many things to choose... (BTW Sorry for my english... I'm italian)
Have a look at the ATmega328 chip, this provide twice the flash and RAM as the standard chip.
maybe there is more that can be optimised...
the 328p is a good suggestion although not officially supported yet
massimo
PS: se vieni sul forum in italiano ti aiutiamo, pensi che siamo li a pettinare le bambole? 
As mentioned the ATmega328 would provide twice the RAM ( 2K ) and flash ( 32K )
The ATmega644 used in the sanguino adds ever more RAM and flash and more pins!
4K RAM
64K flash
If you need even more power and features look at AVR32 chips
buona fortuna con il vostro progetto
The ATmega644 is a good suggestion if you need even more memory and ports than the 328, but note that unlike the ATmega328 it is not a hardware plug in replacement for the standard chip.
As mem said the ATmega644 ( 40pins WIDE ) offers more but will not plug into a regular arduino board ( 28 pins NARROW ) so you would have to get a Sanguino ( http://sanguino.cc/ ) board for it
It will take some extra work to make the ATmega328 work with the Arduino software and even more work to make the ATmega644 / Sanguino work
If you need much more RAM, flash and performance than the ATmega328 or ATmega644 can provide then you may need to look at AVR32 or ARM or something else ( MIPS, PPC, x86, etc )
( Please pardon my Italian )
Ive just run out of memory as well. So Ive ordered a couple of 328 from ladyada pre programmed with a bootloader already on there.
They have a modified arduino ide for windows with the linux version I need to come later.
I wanted to combine 1 wire interface, lcd and ethernet libraries in a project. With the 328 it should all fit.
Gordon
I ordered some from a vendor also
If 32K is not enough the Sanguino is an affordable upgrade ( 64K ), the Sanguino kit costs $25 unassembled plus a $20 FTDI USB cable if you don't have one or a $5 serial to TTL adapter from Wulfden / Modern Device
Hi guys!
First of all I'd like to thank you all for your kind suggestions and replies.
Finally I decided to try the solution suggested by GordonEndersby.
I do think that 32kb should be enough for my project. 
BTW I'm very interested in Sanguino too!! 64kb are enough to develop something "challenging"... maybe as soon as I finish my project I'll start thinking on something "bigger". 
fRA
/me would suggest a 328 a 644 ( sanguino ) and when you run out of resources upgrade to an ATNGW100 