This is a little off topic but I have been playing with the social software application building "playground", Ning. Its great fun and an easy way to test out ideas for social applications, so here is one I made earlier that may be of interest: Window Seat.
Have you ever wondered which side of the plane to sit on for a great view of, say, Mont Blanc when flying into Geneva? Tthe idea behind this application is to share that information and tag it with a 3 letter airport code and 'left' or 'right'. You can quickly check out which side to sit on by looking up an airport or offer your own advice on the best window seat.
I just discovered via Ben Saunders that it is possible to try out rollerskiing very close to home. I have seen people doing this on the back roads of New England as summer training for cross country skiing and always thought it looked like fun. Now I have a chance to try it out.