A record number of U.S. residents went online last month, according to both Nielsen/NetRatings and Jupiter Media Matrix. Nielsen reported a 15 percent year-over-year increase in Web usage, with 115.2 million U.S. residents going online during October 2001. Jupiter Media Matrix, meanwhile, reported that there were 102.1 million unique Web users during the month, the first time its survey has topped 100 million users.