Japanese startup Marketing Resource Center, Inc. started avatar service "Zabtter" which linked Twitter.
"Zabtter" is the avatar service that Retweet of Twitter becomes the virtual goods.
When you do Retweet, you can get 3 virtual goods at random on 1day.
The avatar consists of a background image, skin, wig and clothes.
You can just set the avatar for Twitter icon.
There are 600 kinds of virtual goods now. If you use Twitter and do Retweet every day, you can get a lot of virtual goods. This service is free of charge, but unfortunately it's only Japanese notation.
Please do its best with Googole translation!