AniTuner is a little utility that lets you get really detailed customization of your cursor. With it, you can import animated GIFs or create an animated cursor frame by frame from images. Since Windows Vista lets you set a different cursor for numerous system states, this may sound especially attractive to Vista users. Unfortunately, AniTuner isn't all that effective.
I tried importing numerous animated GIFs --some newer, some that predate Vista- and the resulting animated cursor file was a fuzzy, distorted mess--and the documentation was no help in that regard. After contacting the developer, I learned that only square animated GIFs import correctly, as AniTuner attempts to square GIFs in other shapes, to limited success. AniTuner's built in image editor is too cumbersome to make a perfect square, so you'll have to use an external animated GIF editor to fix them. (Photoshop doesn't support animated GIFs, but CS4 has Fireworks bundled with it, which does.) Squaring the GIF did indeed fix the problem. Another solution would be to use another utility, such as VideoSpin, to break out the individual frames and then import them one at a time, but this seems to be a cumbersome way around a peculiar limitation.
Another troublesome lack: AniTuner doesn't have a pixel-by-pixel editor for frames, relying on whatever external image editor you have set up for the particular image file extension you're working with. I was able to build a cursor from scratch by importing a different image for each frame, but that's as far as AniTuner will take you.
AniTuner is a good idea for an app. However, it needs a few more iterations to smoothly import animated files and turn them into cursors--which is the main reason to download it in the first place.