I've mentioned Auto-Tune before. It's the proprietary name of software that corrects vocal pitch, and is so popular that "auto tune" is the generic name for vocal pitch correction. If the pitch correction is overused, there's an odd warbling sound that was first deliberately used on Cher's I Believe in 1998. The sound is now so loved by those who love this sort of thing that it's used as an effect of its own in many R&B songs, to the extent that my last trip to the All You Can Possibly Stuff Down Your Neck Sushi Bar a couple of weekends ago was actually made miserable by the number of songs using it. After a while it starts to sound as though a robot blackbird has taken up residence on your chimney breast and is determined to drive you insane.
Here's a song that uses the effect even more obviously than is currently fashionable. For comedic purposes, luckily. It certainly demonstrates the eerie Uncanny Valley of Vocals very well.
Talking of vocal pitch correction, here's Hamster on a Piano.
WARNING: Be aware that if you click it, you will forevermore be singing it, and worse, you'll turn into Meghan Daum's worst nightmare, never again free to leave YouTube, searching frantically, like Ahab for the White Whale, for other companion animals rolling on musical instruments - eating popcorn.
Edit 04/06/09: The video has been removed because the person who filmed the hamster sent a DMCA to the person who wrote the song. Aren't people weird.
Here's the film. I rated it 'poor' because the guy made the other guy take down the kooky song.
Here's the kooky song, now with a video about a skunk, which makes no sense.