I'm not the greatest UI designer, in fact my skills are down right poor. However, the UI is one of the most important aspects of any application. It has to be intuitive, flexible, and pretty. Luckily we have Google. Whenever I'm stumped with a UI design problem I type a brief (2 - 3 word) search into Google Image Search that describes the application and/or the functionality I'm trying to implement. I usually receive several screenshots I can use to help guide my user interface design decisions.