Most PDs don't approve of people taking time off after residency. However, if you were doing medicine, I think that wouldn't hurt you too much.
You would end up getting lumped into the category of doctors returning to residency, which is traditionally a less-desired group by programs.
When you are close to graduation you may want to talk to PDs in fields/programs that you were interested in, explain your situation, and see how they react. I think that most PDs will give you a fairly honest answer.
Sounds like a great idea, actually. Most of us can't do that kind of thing because of loans and other obligations, but if you've got the time and drive, I say go for it!