To me it seemed that if you took a year off, you had better be doing something that seriosuly furthered your application. A MUCH easier option is to defer your acceptance. I did this personally, and have several other classmates who followed the same path. We were all serious about going to medical school, but I sure as hell knew I needed a year off. I went through the normal application process, never speaking a word of my thoughts to defer. Once I was accepted, I promptly contacted them on how to defer. I had to write a "petition" to the dean stating what I would be doing and why I was defering. My letter was very simple, something about how I needed to relax (but in much better language, obviously) and would be continuing to work full time as a chemist (which I had done in undergrad, too). They had no problem with it and said to have fun. About Jan/Feb I had to fill out a new AMCAS application (just formality -- I didn't have to write a new personal statement), and then had to submit a letter with my intent to matriculate. All worked out well.
Of the other people I know who deferred, one traveled around south america without and aim and another had an unrelated job (like working part time in a book store or something). None of us feel like these are things you can do if you are simply taking a year off, however.
If you decide to defer, just make sure you continue to do all the things necessary once you are accepted just as if you were actually going to matriculate --- insuraqnce forms, immunizations, FA, etc -- until they infact tell you that your deferral has been granted.