I'm one of those many people who *hate* making accounts for things. I made an account for kaya, and that should be enough. I don't want to give me email and make an account with any third-parties, like 'gravatar'.
Your should implement a system that lets users upload pictures directly :)
Duplicated from “dump gravatar”. The other one has more votes, so switch to that one.
Daniel Wagner commented
I, for one, think gravatar is great. I signed up for it ages ago (I don't even remember what for), and I've been pleasantly surprised on about half a dozen sites or so since then when my custom picture just showed up as if by magic. Their accounts are very lightweight, really don't require a lot of maintenance, and makes this part of account creation very uniform -- no more messing around with crappy custom-built croppers and such, figuring out how to make your picture just the right resolution/number of kilobytes/penis count to pass each site's own requirements, etc.
John Moore commented
already suggested and with higher votes