you are absolutely right, most hotornot sites have that kind of low barrier to entry. my problem is that people who vote but don't submit photos don't really add to the project (not an ad site like hotornot and especially if they vote poorly and are taken out, the votes have to double up for them to have meaning to prevent random voting etc), right now there are actually way more votes than needed in proportion to people who submitted their photos.
Perhaps you three should collaborate or you could simply remove the registration portion and let people start voting from the homepage.