21st-century coupon deals

I've recently discovered Groupon and Living Social, and I don't know how I lived this long without them. (There's also Bloomspot.)

If you don't know, these websites offer coupons to vast groups of people, for everything from helicopter lessons to yoga classes to 50% meals at fine restaurants to Amazon.com gift certificates. I myself have scored two adult movie tickets for $9 (total); $10 for $20 of credit at both Amazon.com and Barnes & Noble; paintball tickets for $20 each; and museum admissions at 50% off. Best of all, you don't actually have to do anything. You put in your email and city at each site, and they email you the daily deals.

But it gets better!

There's apparently a resale market for these already-purchased deals.

For deals that are about to expire, or for people whose plans have changed and now they can't use them anymore, there are Coup Recoup, DealsGoRound, and Lifesta. These sites list second-market coupons that you can buy for a discount off the already-discounted original price.

For people who eat out more often than I do, this is a great way to score meals out for next to nothing.