I agree that it may be simpler to just have 1 avatar across the whole network, but as Rick pointed out,
each site brings out something different for each person.
So my vote goes to allowing different avatars on each site.
My question (which doesn't really have to be directly answered) is,
if it isn't too difficult to implement, could there be a setting placed in the User Control Panel
that allowed you to select Individual vs 1 for all sites (default)?
I personally have been using different avatars on the other sites I've been submitting to,
and by doing so, I don't feel the need to constantly change my avatar every couple of weeks.
(because I like so many of the ones I've made or found)
So if a setting could be implemented, I'm thinking that might be the way to go, and let each person
decide for themselves, and if they feel the need, to change their mind back again.
I tried adding my signature to a few emails once. That's when I learned Sharpies don't wash off LCD screens.