You don't need an account with imageshack to post an image there.
I don't want judges knowing who drew what; last art competition one of the entrants was someone I was a particular friend of, and if I'd been judging I would have been biased towards that person, just 'cus they were my friend, and I particularly wanted them to win
(that's why I didn't step in to judge even when only two of the people I'd asked to judge were able to do so).
Since all the judges are inevitably members of OWF (speaking of which, I need to get on with finding people for that) it could be they'll also have friends and... non-friends entering the competition, and if they knew who drew what, that might influence their decision. Which is why until after the competition I don't want people being able to see who drew what.
After the judging is over you can upload your picture wherever you like, but until then please keep it off of dA or anywhere it might be easily associated with you.
Sorry, and thanks.