Also remember that most people want to be helpful. You can play into that by starting with something like, "I was hoping you could help me get myself out of a little pickle." A little self deprecation combined with a compliment goes a long way, so if you're truly asking them to help you get out of a jam and they're one of the few people that can truly help you, say something like, "boy I really screwed this up and I'm not sure what the best approach would be, but I figured that someone with your expertise could get me reoriented quickly!"