[UPDATE] American Eric Larsen climbed Everest in October 2010 equipped with an Earthmate PN-60w, which uses GPS signals rather than 3G. On October 15, Larsen tweeted "Everest summit," presumably from the mountain's peak.
[PREVIOUSLY] A British mountain climber has sent the first tweet from the top of Mount Everest.
Cool reached the summit on Friday and tweeted triumphantly, despite a "weak 3G signal."
Nepalese wireless operator Ncell installed 3G towers near the base of the Everest in October of 2010.
Check out Cool's tweet (below). For more wacky tweeting locales, view our slideshow of the craziest places to tweet.