One (Been There!): Do what I did in a similar situation... go to grad school!! Of course, being not at all practical, I wrote a thesis about 19th century Lithuanian-American Socialist fiction. Which probably did absolutely nothing to further my eventual (relatively short-lived) career in corporate America. Come to think of it, maybe you should listen to my sisters on this one. Or Mr. One....
Two (Bizarrely Employed): You want to be employable? You've gotta show them you're worth it. What do you care about? Go volunteer at a museum, on a campaign, for your state party. Get involved in your community. Go to neighborhood meetings. Get involved with a cause. Ask your Congressman if you can come in and volunteer a few times a week. Show others how committed you are and when something opens up, they'll want you. It means you can't be half-hearted about it. Throw yourself into whatever you decide to do and do a great job. The more people you get to know and the more people you have the opportunity to serve, the more likely that they will see you as a valuable asset who they want on their team full time.
Three (Nike spokesperson?): Once upon a time *cough* two-years-ago *cough* I was in a very similar situation, and I'm gonna give you the parental "do as I say, not as I do" advice. Get a job, any job, just do something, to stay engaged in the world around you, BUT use your free time wisely. You say you don't have any marketable skills (a statement I highly doubt) use your free time to CHANGE that. Don't be an observer in your own life, if you don't like who you are, or where you're going do something different. Take a course in statistical analysis, and do some research. Volunteer for a local organization that you believe in. Are you crafty? Start an Etsy shop! But also savor this time. Having a job is nice, but it also kind of sucks. You are at a delicious point in life where people won't judge you (too much) for just figuring out who you are, and who you want to be. So, I guess the Cliff notes version is: Just do it, in moderation of course.
Four (Totally useless):
Err. My answers are very personalized, meaning: I'll tell you exactly what I plan on doing in two years when I get to a similar place. I will either a) serve a mission for my church, or b) apply to a bunch of joint JD/MPH programs. Yeah. That's probably not helpful. at. all. But that's why you read this blog, right?
You could also pursue a career as a pharmaceutical sales rep--I hear it's very lucrative (please don't kill me, Two)....
Five (Intended Philosophy Major): Dude, I'm paying as close of attention to these answers as you are.