You can only take up the official o2 insurance within 28 days of purchase...
http://www.protectyourbubble.com/gadget-insurance/
You have to wait at least two months before claiming though.
@Hobo started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
http://www.protectyourbubble.com/gadget-insurance/
You have to wait at least two months before claiming though.