I just read this on hip2save, I have not tried it myself (but will be checking it out later this week for sure!)
If you have a buy one get one free coupon and the participating products for that coupon are priced at $2 or less, the coupon will actually double–making both items FREE!
Some coupons to use:
BOGO Venom Coupon HERE
Buy one Sobe Life Water get one free: IE or Firefox
Buy one Reach Toothbrush get one free from the 4/26RPFind 2 toothbrushes priced at $2 or less
Buy one get one free Rimmel Nail Polish from the August issue of All You mag.
Buy one Snickers, Twix, Milky Way, 3 Musketeer, etc. get one free from the 8/2RP