I took a gap year and re-applied for 2014 entry after getting 4 rejections in the previous cycle. This year I have an offer from Manchester, but was also rejected by the other 3.
I have been working as a HCA since July (break after exams? what break?) and been loving life taking a break from school and sixthform, being filthy rich compared to my poor student friends (whom I go up to see every couple of weeks and go completely wild just because I can) and blowing all my money because this will be the only time I have no responsibilities.
I do however think it is also crucial to mention that taking a gap year + HCA still doesn't mean jack **** if you don't apply to the right places. And sometimes, you can do everything right and still not get in. There are a few people that have reapplied this year that are either on a 2nd gap year, or are considering taking one. I, for example, only just made it into Manchester with a UKCAT sitting on the cut off.
As someone halfway through the year, a bit of advice:
If you do take a gap year, make the most of it for what it is. Don't make it only about reapplying for medicine, make it about other things too because if for some reason you don't get in, you will become bitter and angry that you've "wasted a year".
Also, be prepared more than ever to do another course. You might not get an offer for medicine, but there is nothing more uplifting than knowing you'll be starting university for a course that you love in a place you love no matter how your medical application pans out.
But before all of that: get AAA.