Have a look at .. url deleted
Its a little different from the majority in that it is an online logbook ie you can access it from any computer on the net, and you have no worries backing up all the time or losing it all should your computer crash.
Its CAA approved. I can personally recommend it as I've been using it for the last 2+ years. Very importantly, the back up support is second to none.
Edited for advertising .. the url reference shouldn't be too hard to find for those interested .. a UK crowd with a not too difficult combination of pilot and log(book) ..