I'm new to this also, but I'm really excited about it. Actually, telling people I'm an agent hasn't been an issue for me. I've blabbed to everyone about it. I guess if I get to the point where getting to do campaigns and I'm Bzzing people that I don't know, I'll just tell them that I got to try such-and-such through BzzAgent and I think ____________ about it. Maybe something like, "You know, I just got some of X through the mail with BzzAgent. I really like it. They gave me some samples to pass out. Would you like one?" then let it go from there.
I hope that helps. Now I just needs some campaigns!