Saw this in the local Metro paper yesterday. Something to do with celebrating the new Indiana Jones movie you can get 4 free o2 sim cards (the ones with all the free texts - i think 300 when you top up £10, 500 when you top up £15) sent to you.
All you have to do is text:
Jones + your title + name + full address
eg. Jones Mr John Smith 1 england road england e1 1ee
Hope this helps someone