Why can't we like register for a real username and use it to login and play? I think there should be score keeping and a rank system for the top highest scores.
and
There should be an option where you can upload an avatar instead of just typing in a url..

You can join the registration discussion here (http://www.isketchforum.net/registration-t1955.html).

There's a few things that could be done with registrations like you mentioned; examples are talked about here (http://www.isketchforum.net/isketch-survey-results-t1696.html?t=1696) and here (http://www.isketchforum.net/registration-t1955.html?p=108340).