Paid User Pictures
Short, concise description of the idea
Pay a little more per month to have more user pictures
Full description of the idea
Well this is like different from true paid accounts, really... but perhaps like a user can pay $1.00 or so more a month (whether paid account, free account, etc.) to be able to use more user pictures. That way, a) there's no problems of having the pic hosted elsewhere, b) the LJ user benefits, and c) LJ benefits. The user is basically paying for more space? to have more user pics.
An ordered list of benefits
An ordered list of problems/issues involved
An organized list, or a few short paragraphs detailing suggestions for implementation