O2 (UK) Telefónica O2 had a long-standing relationship with Arsenal F.C., being their shirt sponsor until the end of the 2005/2006 season. In 2005, a three-year deal was signed that saw Telefónica O2 become the team's exclusive mobile communications partner. O2 were the main sponsor of the Channel 4 reality TV show "Big Brother" from its second series (as BT Cellnet) in 2001 until its fourth series in 2003. They also sponsored the spin-off shows "Celebrity Big Brother 2" in 2002 and "" in 2003. In total O2 sponsored five series of the show. O2 sponsored music festivals, the Wireless Festivals, from
O2 (Ireland) Ireland and Three Ireland, offering services in some built-up areas in late 2006. In July 2007, O2 launched its mobile broadband offering in Ireland using HSDPA technology over its 3G network. They provided speeds of up to 7.2 Mbit/s and claimed to cover 90% of the population on the least contended Irish 3G network following an upgrade in 2007. Speak Easy was the name of O2 Ireland's prepaid service. In 2007 they became the first Irish operator to offer free text messages to all Irish mobile numbers, although it only applied for weekends. However, in early 2008 they introduced a