I have a long list of back-to-school supplies pinned to my bulletin board. I love to shop online but I usually haul the kids to Target and let them paw through the bins and select their own binders, pens, and composition books. I’m pretty sure this is not the most cost-effective way to do this. I always end up funding at least one pointless investment: Hello Kitty pencils, a highly-fashionable-but-ultimately-useless backpack, or a scientific calculator no one needs since you can just download one to the kid’s Netbook.

But this year, I may reconsider this plan and take my school-supply shopping digital. The folks at Microsoft’s new search engine, Bing.com sent me a note this morning saying, “Bing shopping and cashback will offer significantly higher cashback percentages from select participating merchants starting on August 10.”

Cashback? How have I not been doing this?

You have to sign up at Bing cashback first. That was a matter of logging in to a Windows Live account (or creating one) and entering my mailing address (presumably so they can mail the checks!)

Next? Start shopping at Bing Shopping. For example, “backpack” is at the top of my supply list. So I started at Bing Shopping , searched for “backpack,” and got a long list of choices. I saw one I liked, clicked on it and got this screen:

There are my choices of merchants who sell this backpack. It tells me right up front which offer free shipping and what each store charges so I can quickly compare. It also tells me what percent of that purchase price I will get back for shopping via Bing cashback. But today, Bing tells me I would get 11% off at eBags.com on this item. According to the email I got this morning, though, that cashback amount will be 30% from eBags.com for a limited time starting on the Monday (August 10.) There are lots of other merchants — HP, Sears.com, Barnes & Noble Inc., Overstock.com, Foot Locker, and others – offering higher percentages during this promotion too.

I think I’m going to skip the Target outing this year and aside a little time to do some online shopping on Monday. How about you?