This deal is pretty simple: just buy 3 specially marked boxes of Kellogg's Mini-wheats, All Bran, or Raisin Bran to send in codes for a $10 rebate. These "bonus bucks" are usable in certain stores (see list here). There is a great $1.50/2 coupon available for the above cereals at RedPlum.com (print it twice). There's also time to wait for a sale because this offer doesn't end until September 30.
**I'll be honest, I've never had any lucks with this type of deal before. I'm lucky if I can track down ONE specially marked box. However, I am more hopeful about this one: the deadline is long and four different cereals are eligible. Your experience may vary.**