I really like this tilt-shift video of Chicago, which I found via @SMWChicago. Tilt-shift miniaturisation seems to be really popular at the moment. I've seen a lot of photos posted online and elsewhere, but I didn't really understand how it worked. So I found a great article on cow.mooh.org that explains both tilt-shift and tilt shift miniaturisation. There's also related articles that include a DIY Guide to Tilt-Shift Lenses, and Shooting Tips and Results.
If, like me, you aren't very good at DIY then check out this inexpensive tilt-shift camera at Photojojo, or the Photoshop tutorials at Visual Guide and Tilt Shift Photography. If you have an iPhone, check out this list of tilt-shift apps at Digital Photography School. I'm not as familiar with Android apps, but this Mashable article lists Camera360 as a good tilt-shift option.