I did exactly what you guys are doing, when I applied to go to Uni 2 years ago. I didn't get the grades to get into my first choice, and didn't fancy going to my insurance so took a year off. And man, I'm SO glad I did. I retook an A level to improve my grades, got a full time office job at Prudential (its so great earning lots of money!) and then went travelling. The great thing about retaking in January was that I had my grades early so I rang up the University and asked them to accept me as I had the grades, this meant no pressue in August! I ended up going to a different University to the one I originally intended to go to, mainly because they were horrible, and now I'm having a fantastic time at Nottingham!
Seriously, I know you may all feel a bit crap about not getting in, I definitely did, but it all worked out for the best. I had an amazing Gap Year, got lots of money (which school leavers don't :-), matured SO much and it just seems you appreciate Uni a lot more because you're older, wiser and richer!