I spent some time this afternoon poking around the Dallas Semiconductor web site, and ordered a One-Wire Weather Station Kit. Keichii is excited about helping, so I'm going to plunge into the early design work for a project I've wanted for a long time, my OpenSail project.
The initial goals for OpenSail are quite modest: given a wind direction and velocity from the One-Wire weather kit, and boat speed and direction from a GPS via serial/NMEA output, calculate and display the apparent and true wind speed. Later, we can add features like wind tracking, performance vs. polar plots, layline tack alerts, lifts, etc.
I spent some time poking into libvgl for graphics output, but that would limit it's portability. Since I'll probably run it on my VAIO, I think I'll stick with X for output. A friend at work suggested writing it in GTK-, since that will be good experience. I'll look into it more this week while I'm off work.
I wish I could afford to just do this full time.