Hi, in November I purchased a MacBook and have been adding a lot of large files from video capture and creating movies in iMovie. When I first bought it it would boot up fast and load programs quickly. But over the past few weeks, this past week in particular, I've noticed it is taking much longer to get to the desktop and load applications. I am wondering if there is some sort of defrag utility I can use to help defragment my files to help make my MacBook run as fast as it used to. Or better yet, is there another type of clean up utility that I can use that would be more preferred than others? Thanks in advance.