[babaloo999]

LOL. What grade are you in?
Seriesly(you read that right), answering machines are quite useful for telemarketers.
If a number doesn't show up on caller id, I let the machine get it. They generally don't leave messages unless it's a recorded one.
I do like some posters' idea of wasting their time by stringing them along.
That's if you also have the time to waste.
Cheerio.

[NautiNurse]

One of my personal favorites is to ask for the caller's name, wait for a moment while they dive into their monologue, then in my most sultry voice, "[Caller name], what color underwear do you have on today?"

[killjoy]

That's if you also have the time to waste.

Not true, takes almost the same amount of time. Just set the phone down on the counter, come back about a minute later and then hang it up. You just took up probably 1000% more of their time then if you just hung up the phone initially. That is 10 people that didn't just get called during that time period.

[MrLeRoy]

answering machines are quite useful for telemarketers. If a number doesn't show up on caller id, I let the machine get it.

I use this system, and I can't remember the last time I had to talk to a telemarketer.