I'm gonna give some different advice that some people here have given. I started on a Specialized Expedition (comfort/hybrid) and I outgrew it quickly. So quickly that I bought a Specialized Allez 3 weeks later and sold the Expedition. I think, unless you're wanting to buy a Madone/Tarmac/etc., which I wouldn't recommend for the reasons that others have stated, I say go for it man. Go to your LBS and try out some sizes and see what works for you. If you wanna pull the trigger on a bike there, go for it. If not, then go used.

They're light, fast, and fun. You'll be able to get around much more quickly. Everyone that I saw when I was a college student rode Walmart mountain bikes. I always thought that was ridiculous given all the sidewalk riding they did. Anyhow, just my $.02.