Neither Amazon nor Sony offer Wi-Fi capability for their e-readers. Plastic Logic (pictured), on the other hand, promises to have Wi-Fi with its reader. All three makers offer or will offer 3G wireless connectivity through at least one device, Amazon through Sprint and Sony and Plastic Logic through AT&T. Amazon's Kindles do offer Web browsers, where Sony's and Plastic Logic's Readers do not, or aren't set to.
Advantage: Plastic Logic