Skimming in FCP X is one of the things that I really miss when I’m in other NLE’s, particularly for previewing effects and looking at individual clips in composited piles of video. Here’s a little video that compares the difference between skimming in FCP X, and similar options (if any) in other NLE’s. If you use X this isn’t new info, and if you don’t… here’s the difference.
Final Cut Pro X Babbling 