To summarize (I thought this might go better in another post):
Ease yourself in!
1) Go somewhere where you know the help. It's a little easier than approaching strangers, at first.
2) Dress the part, or don't. I wore a red tee and some jeans, and the only person I heard mentioning it thought I was an undercover :shock:
3) Act the part, absolutely. I look, if one takes a small leap of unassuming logic, like a soldier/cop/bouncer, given the haircut and the weight lifting habit. But walking around like I was toting extra brass in my pants is really what I think did the trick.
4) If you can't meet people you know, take people you know. A big dog running around loose is cause to take notice - a big dog running around playing frisbee is just having fun.
5) Above all, try it, sometime, somewhere. You may well be surprised by the results.