At CES 2009, Dan got his hands (or eyes?) on Vuzix's Wrap 920AVs that I was getting excited about here. They're every bit as awesome as promised, apparently, but Dan also managed to wheedle out a price from them - they're looking at $399 (£274), and a 'summertime' release (for the US, presumably).
Related posts: Next-gen Vuzix VR glasses will be unveiled at CES | Vuzix Wrap 920AV audiovisual goggles - the full, actually quite awesome, details

Indeed, very nice, but seeing that the iPhone/iPodTouch ONLY output the video player, and NOT google maps, GPS, PDFs, games etc, the iPhone wont be the platform for turning these into true visual augmentation.