The following from http://wyatt67.edublogs.org/2008/09/28/week-2-avatars/

Any age can use these avatar sites:
From abi-station:
If under 13, sorry you can’t register for these. But over 13, need parental or guardian permission.
Thanks to this wiki which gave me many avatar websites to visit.


and some more from Plurk buds:
http://jbsites.googlepages.com/avatars
http://illustmaker.abi-station.com/index_en.shtml
http://www.weeworld.com/