If you're interested in a sure thing in a computer technology investment I've got a hot tip for you -- a guaranteed 57% return. Not only that, you get a cool laptop and a tax break just like you were buddies with George Bush (if that idea appeals to you). Your cost? $423.95 and a postage stamp. Here's how it works. (I'll explain the stamp later.)

First you go to www.laptopgiving.org and follow the prompts to pay $399 for two of OLPC's XO laptops, plus $24.95 shipping: a total of $423.95. You're paying for two XO laptops, you get one, and you're donating the other one to a child overseas -- which currently means Afghanistan, Cambodia, Haiti, or Rwanda.

Of the $399, you get credit for a $200 charitable contribution. Next April you can deduct that from your taxable income. If your tax rate is, say, 20%, that's a savings of $40, which brings the actual price of the XO laptop you receive down to $183.95. You even get a nice e-mail from Nicholas Negroponte, founder of OLPC, thanking you for your contribution.

Now, here's the really good part. If your company has a matching gift program you fill out one of its forms and mail it to OLPC (that's where the 41 cents for the stamp comes in) and the organization gets another $200, for a dazzling 100% return.

(And if your company doesn't have a matching gift program, ask why. Loudly and often. It's a great way for you to get that cheapskate outfit you work for to pry open its wallet and spend a little for something you think is important, instead of CEO bonuses.)

That's all there is to it. You get a fantastically interesting piece of technology for a mere $159.95 plus shipping, and the $40 you save on your taxes plus the $200 your company contributed to One Laptop Per Child is a 57% return on your original investment. QED. But you do need to strike while the iron (or at least your credit card) is hot: the "Give One Get One" program is set to expire Monday, Nov. 26.