London's 'free' Wi-Fi flips the switch, but you might want to upgrade

But "free" might be just another word for "captive audience," as the free network, which is marketed as Online-4-free.com, interrupts users every 15 minutes to play a 15- to 30-second-long ad. That would be enough to push most folks up to the pay version of the London network, which offers a 500Kbps connection, double the free version's 256Kbps, for a quite reasonable £9.95 ($20) a month.

"This really marks the arrival of free Wi-Fi in Greater London," said Dan Toomey, chief executive of Free-hotspot. "Millions of Londoners, as well as commuters, visitors and tourists, can now expect to find free Wi-Fi as they work or play along the Thames."

Free municipal Wi-Fi is spreading throughout the UK and Europe. Norwich, England, launched a city-funded network last summer and Manchester is slated to launch one next month. Paris is building a free citywide network in a public-private alliance with Alcatel-Lucent and SFR. Many other fee-based networks are available throughout the UK, with many built by British Telecom.