On February 20th, the folks at VectorMagic broke off from Stanford University and went live with their own site.
If you haven't checked this site out yet, you must! It does an incredible job — many say way better than Illustrator's Live Trace — out of converting raster images into vector artwork, ready for downloading. Feed it the worst 72 ppi web graphic or digital photograph you can find, and get a resolution-independent, path-type illustration in return in EPS, PNG, PDF or SVG format.
When the computer geniuses behind the site were sponsored by Stanford University, the service was free. Now that they're on their own and have to pay for their own servers, you'll need to pay a "token" for each image you submit. Your first two tokens are free upon registration. Use them to test it out, and if it's worth it, you can buy tokens for a buck or two a shot.
If you register by March 5, you'll get two additional free tokens, for a total of four.