I don't know whether to laugh of cry. I hold out for these microdisplay-integrated glasses and, while I'm waiting, I'm expected to make do with this stick-on monstrosity from Arisawa. Yes, it only weighs 8g, but unlike the Lumus-Optical pair linked to above you'll only get a 21-inch virtual screen (compared to 60-inches) when viewed from a meter away.
On sale in 2007, with a Japanese TV tuner-equipped model following after, they'll cost around $429.
They come with a box of gubbins that can accept input from video-capable iPods and have a rechargeable battery with unknown life. The lens attaches via a suction-cup.
If it's okay with you, I think I'll pass on these. While I'm a brave boy, I don't think I could cope with being seen in public wearing them!