i, too, took a year off between my first and second years of medical school. I did it for multiple reasons, but mainly to reevaluate and refocus my decision to go to medical school. I ended up doing cutting edge research in a really fun city (Boston), at a great institution, with amazing people who i now consider good friends/mentors. but most importantly, it gave me a chance to really figure out what i wanted to do in medicine and really with the rest of my life.
as for it's impact on residency applications, i believe that it can only help you as long as you can justify the time off. be sure to learn something from the experience. i'm in the midst of applications, and have yet to interview, but have been asked on my away rotations about my year off. i've only had positive responses, and feel that it separates my experience from a lot of my peers. in fact, there is a portion on eras to explain any leave of absences--which i filled out--and have recieved plenty of encouraging emails/interviews from programs.
i personally feel everyone should take a year (or 2 or 3) during their medical education to pursue something they enjoy....cuz as soon as residency starts....it's all over!
enjoy your time off! it can only help!
-digimon