Retrievr is a really cool image search tool. You draw an image on your left and it will automatically return images from Flickr that resemble what you’ve drawn. I agree that Google Image Search should implement this mode. Via Google Blogoscoped.

The Song Tapper is a Flash-based tool that let’s you search for a song by tapping its melody using the space bar. The songs are taken from a user-contributed database. I tried it on three songs—"Always Be My Baby” by Mariah Carey, “In the End” by Linkin Park, and “This Love” by Maroon 5—and got the last two correctly. I’m impressed. Via Kottke.