In South America, you can find harpy eagles with talons the size of grizzly bear claws. Sounds like they'd even freak real Harpies out. (Source.)
If you're into World of Warcraft, then we're guessing you've run into a Harpy or two. (We hope you clobbered them.)
The word "harpy" is sometimes used to describe any nagging, ill-tempered woman. (We suggest you don't use this one on your Mom.)
You definitely don't want to runs into a "scream" of Harpies if you're playing Forgotten Realms role-playing games.