Do you know what you want to do in your lag year? I found it fairly easy to find a research position when I decided I wanted one. They don't pay too well, but it's enough to live on, and maybe you could get a few publications before you matriculate to med school.
Wherever you are going to live for the year, target a university with a major medical center in the area and apply for open research positions there. Make sure your resume highlights relevant experience and make sure to ALWAYS include a well-written cover letter SPECIFIC to each position that you apply for. In your cover letter, spell out your goals (I'd specify that you have a year to commit before med school, but that you are interested in getting some good research experience in the interim). Describe what qualities you would bring to the lab that are relevant to the job. If there is something that might worry the hiring officer about your application, I'd explain it too. For example, if you are applying for jobs at UCSF but you live in DC, or if you are somehow crazily overqualified for the position.
I'm currently screening candidates for a position in our research group, and we can only interview so many, so I'm wary of several things, esp: no cover letter, cover letter is general (probably applied to all research positions at the university, rather than specifically interested in our opening), applicant doesn't specify why they are interested or what thir goals are. Also, unless you have no relevant previous employment, I'd avoid including much non-related experience in your resume/application.
Hmmm... I can't think of much else right now, but if you like the research idea, I can tell you that there are always PIs out there who are looking for eager students genuinely interested in their research.
Hope that helps!
-lion
