This is a trick I like when I have time to kill and some one calls with a survey. You make them a deal; for every question they ask you get to ask one, usually they will play along. This is fun because now you are wasting the money of the higher-ups and both you and the guy on the other end can sit back and have a conversation. I have found that most people doing the questionaires are starving students like me who have taken a temp job.

Another one I like is when someone calls to sell you something try to sell them your old lawnmower or something. Have fun with it.

Finally if you are really in a bad mood pretend to be an employee of the FCC. Asking them for their home phone number has been done so many times they expect it, but just for shits and giggles incorperate the two:

Hello, this is Phil. I have a deal for you on an electric curtain pull.
Hey, Phil this is Dave. Tell me, what is your home phone number?
I.. umm, I don't think that is really relevant
Oh, Phil, of course it is; in fact I think it's only fair. I mean, you have my home phone number, why shouldn't I have yours?
I umm well...
Tell ya what Phil, let me talk to your boss. Is he there?
Well, actually he stepped out for a moment (note: the boss is never out of contact)
Really, well did you know I work for the FCC? Do you have any idea how many federal regulations you are breaking right now? I want the name of your company, your boss' full name and your full name, right now.
Oh, here's my boss, he just walked in.
Hello, this is Jake, the Supervisor.
Well Jake-the-Supervisor, I was just telling Phil that I work for the FCC....
You get the idea.

Once I got all the way up to one of the company's vice presidents before they caught on. He threatened to press charges

"Really, you want to admit that more than half your company was outsmarted by some dumb college kid? That's pretty ballsy of you." *click*