Cool, all Georgia roadies so far!!!
Good call mxer, I bought my Cannondale CAAD6 at Atlanta Cycling in Vinings back in 2002, the service is the best that I have found in Atlanta.
D, any decent shop will let you take the bikes that you are considering out for a test ride. And like mxer said, have them fit the bike for you.
Being a Cannondale junkie, that is what I would suggest to you, I have 2, and I love them like they were family . Of course, any of the big names out there (Trek, Specialized, Giant) have models to cover nearly every price point, so you could probably spend an entire weekend just test riding the different brands. Just make sure that you choose wisely, when I first got into road bikes, back in 2001, I was so excited to get started, I bought a Schwinn Fastback on a whim (mainly because I was able to get an employee discount). It was a nice bike, but after a few rides, I decided that I just couldn't get used to the compact design (ended up ebaying it and bought my Cannondale).
Good luck, let us know what you end up going with.