This may fall into the more-trouble-than-it's-worth category, but here goes anyway....

Use a cash-back rewards credit card to buy gift certificates. (1% off the top right there--McDonald's recently started accepting credit cards around here!) Sign up for upromise.com and get a 3% redemption on your gift certificates.

Now, I'm sure you're thinking: 1% + 3% is 4%, not 7%!

Choose one item from the dollar menu. (My favorite is the McChicken sandwich.) This is about $1.05. Pay with $2.00 in gift certificates. Get 95 cents CASH back. Repeat five times. You spent $5.25 for 5 McChickens, burning through $10 in gift certificates in the process.

The rebate is 3% of $10 (30 cents) plus 10 cents rebate back. The percentage savings is $0.40 / $5.25 = 7.6%.

A really strange spend-less idea, from your friendly neighborhood Mighty Bargain Hunter.