So I'll start off with my experience. I have done a few projects with the Arduino Dueminalove. Naturally after I recieved it I did the blinking LED. I made some controllers and fiddled with Pong. I setup a small LED array. I played with a couple morse code projects using an LED and a small speaker scavenged from a computer. My current project is a Reprap 3d printer. I've got it running though not printing yet. Still working on getting the non-standard, horribly documented Techzone firmware working for the heater and thermocouple for the tip.
I was looking at the DIY drones and other RC type projects and stumbled across a news piece about the Lunar X Prize contest. It got me thinking and while the funding to get it to the moon really isn't feasible the idea of making an open source rover that includes an Arduino in it and testing it in extreme conditions would be fun. I plan on having some funding to start building a prototype in November. The first prototype I'd like to build with regularly available RC parts along with easily fabricated parts to work out the basic communication and controls and then work on making it more durable to withstand harsh conditions afterwards. I have been thinking something like the Linux stamp might be good for the main board and I am licensed amateur radio operator so I plan on using the ham bands for communication and control. If the idea appeals to you I am looking for help with the overall design and with my project website.
Any help, sugestions or ideas would be appreciated.