Geek: Yup, nailed it. This word is everywhere, including its horrifying verb outgrowths ("I'm geeked!").
Icon: A New York Times writer provides a strange window into the world before icon meant a part of a graphical user interface. "Readers of this dictionary will find 'icon,' defined not as a religious picture but as a small symbol on a computer screen."
Infobahn: This synonym for "information superhighway" never caught on. Too German sounding for American ears, I reckon.
Infotainment: I'm pretty sure videogame developers came up with this word to sanitize their wares for parents. This word's still floating around, and I wonder if it could be profitably attached to the current generation of MOOCs.
Glocal: Global + local. Eww. This was coined in the early '90s and is enjoying an improbable resurgence to describe some types of business models.
Hunt and Peck: The slow way of typing is still recognizable as a phrase, but as more and more people type faster and use smartphones/tablets, we seem to have fewer opportunities to use it.
Karaoke: A spectacularly successful entertainment technology experience, the original noun is now a verb, too.
LOL: This rather contemporary sounding term made a dictionary way back in 1998, when I was LOLing and ROFLing in chat rooms across the Internet.
Mouse Potato: This play on "couch potato" didn't make it many places outside the Oxford Dictionary of New Words.
Nerkish: Another missed opportunity! Formed from nerd and jerkish, it describes a substantial portion of the Internet.
Netiquette: This word appears to be used by newspaper columnists and grandparents. It's fallen out of common usage.
Netizen: I guess people sometimes use the term, but the spirit that infused it, this idea that the net was a separate space, an independent country that you could have citizenship in... Well, yeah, the NSA thought that was cute, and made sure to tap the pipes on American soil.
Palmtop: Appearing in Webster's New World Dictionary, this word never caught on, though, with the rise of the old smartphone, we're all living in the age of the palmtop. (What the editors didn't see coming in 1992 was that we'd hang on to the word "phone" for devices that are used far more often to do other things!)
Pharm: This term was supposed to mean a place where genetically modified plants and animals were raised. But that would be most U.S. corn farms, for example, and you don't see the term applied.
Phone Sex: Still around, though I think it's lost its 900-number paid-for connotation. Now, the meaning seems more like "voice sexting."
Phreaking: Phreaking was hacking the telephone system, essentially, and it's a classic term that's becoming obsolete because a smaller and smaller slice of our communications run through the infrastructure phreakers investigated.
Publify: I LOVE THIS ONE. Publify was meant to mean "publish online" or in a database. I can't wait to publify this post. Please help me bring this into common usage. Tell your blogger friends.