Yes you can. Install maniacbug's core files into the IDE, select Bobuino as the board type, and have more RAM, FLASH memory, IO, all ready to go.
I have 19 boards on hand still.
Reply #224 at the bottom of page 15 has the details
http://arduino.cc/forum/index.php/topic,80483.210.html
with a parts line in #313
http://arduino.cc/forum/index.php/topic,80483.300.html on page 21