This page will continue to be a work in progress, until it isn't. But what can you do?
I tend to be a little reserved when around people I don't know all that well, but I get more gregarious once I've had time to get comfortable. Expect sarcasm and puns in roughly equal measure.
As to general attitude, I used to be a "t-shirt and jeans" guy, but moved on to "t-shirt, slacks, and an overshirt" (aka "business lazy"), though I don't have a problem throwing on a suit and tie or just a blazer if things need a little class.
A lazy afternoon reading or catching up with friends is more interesting than a long hike to me, but suggest something to pass the time and I'll likely be interested.
I'm an avowed geek and I work in the video game industry, so I tend to be up on the latest happenings, even if I don't play a whole lot at home anymore and don't touch MMOs with a ten-foot pole. If you've got similar interests, great! If not, that's also great. Different strokes for different folks.