
It's £54.99 to renew (!!!) so if you're running version 1.0, you might as well buy the new 2.0 -that's what I did. :) Was much the same price! (Just checked and PC World charges £54.99 if ordered online, £59.99 if bought in the shop.)
http://www.symantecstore.com/dr/v2/ec_MAIN.Entry17c?SID=27685&SP=10023&PN=80&PID=918414&V1=918414&CID=208090&CUR=Or you can renew via the programme. Just start Norton, and click on Account, and there it is.
The good point about 360 of course is that it is a license for 3 users to install it on different computers so you can get together with someone and share the cost -again that's what I do.