I've had my Pi since May and have tried a few things, mainly with a degree of success. In order to keep track of what I've done - and help anyone else who may be wanting to do something similar - I thought I'd post a few pages here. Most of what I've done is by using information found elsewhere on the internet - I've just gathered the information here and where possible I've linked to the original source.
I have actually had three Pi's - the first is in use as a web server (not this site) / robot arm driver, the second was unreliable with frequent crashes. I found that by putting in the oven for 5 minutes at 150 deg C helped but the SD card holder eventually became brittle and snapped. I've super-glued a failed SD card to act as a holder for the SD card - but SD cards don't like getting hot. They tend to twist and melt a little....
Pi number 3 was one of the first REV 2 boards off the production line so only has 256MB of RAM - and led me to develop some model and revision sniffing sofware.
The Pi has been a reason to learn linux, and my programming language of choice is Python. I've mainly used my Pi for sensing the world around it using GPIO's and giving some sort of feedback using LED's / LCD displays / driving motors.
I very rarely (if ever) connect my Pi's to a screen, preferring to ssh into them. If I need a screen, then I usually use VNC.