I just recently read something that said if you hit a plateau, you should do something drastically different from what you're currently doing to "shock" your body into losing the last few pounds. So if you've been running, you could try swimming or biking or something. Or if you've been focused on weight lifting, you could go hiking?
Just throwing some ideas out here... Have you tried to reduce your caloric intake a little bit more to see if you could squeeze the last few out that way?