For those of you who are working with the Arduino Duemilanove, you might be interested in this announcement from Arduino about a processor upgrade.
“We’re very happy to announce that the Arduino Duemilanove has been upgraded to a more powerful microcontroller: the ATmega328. It’s fully compatible with the previous ATmega168, but with twice the memory. That includes flash memory for storing sketches (32 KB instead of 16 KB), RAM for holding variables (2KB instead of 1KB) and EEPROM for saving data when turning off the board (1 KB instead of 512 bytes). We’ve also raised the speed (in the bootloader) for uploading new sketches from 19200 baud to 57600 baud.
“Thanks to some tough negotiating by Gianluca Martino of Arduino and Smart Projects, this won’t raise the price of the board. Look for distributors to roll out the upgraded boards soon. Current Duemilanove or other Arduino boards can be upgraded by replacing the ATmega168 with a bootloaded ATmega328 (you’ll need to buy a pre-bootloaded one or use a hardware programmer). Be sure to select “Arduino w/ ATmega328″ from the Tools > Boards menu.”