iTunesCheck is a program that I wrote after checking out several other programs and not finding exactly what I wanted. It provides global hot keys for controlling iTunes without switching to it, it provides a hotkeyable floating window that shows the currently playing song, and it provides a hotkey for quickly finding a song without switching to iTunes.
Yes, all of these things are, of course, available directly in the iTunes interface. But I find it cumbersome to have to switch to iTunes just to figure out what song is playing. This is faster.