Jess,
One of the hardest questions I was ever asked was "what are your strengths/weaknesses". I babbled through not wanting to blow my own horn or seem cocky in the strengths department nor did I want to put myself down in the weaknesses dept. I can't even remember what I've said in that instance.
Recently, I was called as a work reference for a woman who worked for me. They asked me the same of her. I told them that her strength was that she was a very hard worker, great attention to detail, blah, blah, blah. I said her weakness was that she was sometimes too hard a worker- always staying late to pick up the slack....etc. She got the job and her boss told her it was my recommendation that got if for her. He liked the answer to that question.
Too bad for her- he works her like a dog. She should have stayed with me. I pay way less and can't offer benefits, but I'm nice.
Good luck !