Twitter co-founder Jack Dorsey confessed to WNYC's Lisa Chow and Jim Colgan that his name-choosing strategy for the company consisted of rummaging through T and W chapters of the dictionary:

DORSEY: We wanted a name that evoked what we did. We wanted something that was tangible. And we looked at what we were doing and when you received a tweet over SMS, your phone would buzz. It would jitter. It would twitch. And those were the early names, Jitter and Twitch. And neither one of them really inspired the best sort of imagery.

[snip]

One of the guys who was helping us build and create the system, Noah Glass, took the word Twitch, and he went down the dictionary. And we all looked at the Oxford English dictionary at the T-W's, and we found the word Twitter. And Twitter means a short inconsequential burst of information, chirps from birds. And we were like, that describes exactly what we're doing here. So it was an easy choice, and we got twitter.com for some very low price, and we named the company Twitter.