O2 has been hit by a serious failure, with reports coming in from around the UK of the network disappearing and its status page conceding some network problems.
The trouble started mid-morning with phones dropping off the network, but the problems aren't location specific so it seems some sort of central server is again responsible.
Last time it was network attachments which were faulty, so those who remained on the network (without power cycling their phones, or moving too far) continued to receive service, though occasional reattachment is a normal part of the GSM protocol so eventually everyone gets kicked off.
We don't know if it’s the same problem this time around, but the best bet is to keep any O2 connections switched on - unless one fancies an early pub arrival in which case power cycle away and blame O2, for as long as you can. ®