From the website:

Create.
Meez are about you expressing yourself online - and having fun doing it. Go ahead. Select a skin tone. Add a hairstyle. Go wild with different outfits and accessories. Meez gives you millions of potential combinations, so you can create a look that shows off your unique style.

Animate.
Meez characters are 3D, and they've got moves. So strum a guitar. Kick a soccer ball. Or just lounge on the couch. Whatever you're into.

Export.
Once you've created your Meez, it's time to get out there and show your digital self to the rest of the world. Use it as your personal I.D. when you're on IM or messaging in your favorite online community. Place it in your blog. You can use your Meez on any site or program that accepts digital images.