I was sort of forced to take a "gap semester" which is what I'm doing now. I got accepted into my #1 in the Spring 2010 semester, so it was either that I could take classes at another school during this semester, or just wait it out. I didn't want to deal with the credit transfer issues that were arising, so I decided it sit it out this semester.
So far, I am enjoying it. I'm working full time at my university, so I'm there anyways and saving good money for when I get there. I got Scuba Certified recently, which has been a goal of mine since I was 10. I started a band with a few friends and we're beginning to play shows, I got some new hobbies like astronomy, started writing some original music and recording it and mixing it on my computer, and I bought some review books related to my major to look over to keep me fresh. Many of these things I wouldn't have had time for had I been going to school and had to worry about homework and tests.
So all in all, I'm definitely making the most of it, and it's been a good experience. Would I recommend a whole year of it? Not at all, I can't wait to start school in January. However, if you really want to get a glimpse of it, just defer until the next semester and take the first semester off. Again, definitely look into what you're getting into before doing this: I'm down four classes, which I will still have to make up (I got to a five year school that runs two half semesters in the summer though, so I have it a bit easier).