Michael Schubart shows how his cell phone can read a URL from a computer monitor using 2D barcode technology (QR Code). 2D barcodes contain information in both directions — horizontal and vertial. QR Code is similar to the kind that UPS uses (Maxi Code) except that it can contain way more data.
And, just for the hell of it, here's the QR Code for my website address:
Of course, I have no way of knowing if this works as I don't have a wicked-cool Japanese cell phone, but I just had to try it out (link's to QR Code encoders are available on Michael's Wiki).