If you don't have a photograph for your avatar, or would prefer something a little more cartoony, you can make 3D steampunk avatars at Meez
. It's free to sign up and you get free coins in their newsletter, which you can use to buy outfits. There are free outfits you can start off with until you gather some coins. You can also design your own background... with or without TARDIS.
Here are a couple I created earlier.
Unfortunately you can't export the full animation. You can see my animation with flying TARDIS here.
The only bad thing is that these avatars have much nicer clothes than me! Is it wrong to be jealous of pixels?