Other than my documents/pictures folder in the iMac at home, I dont have anything of any real value to bother backing up on my home computers.
My docs/pics are locally copied to an external hard drive whenever I remember to do it. Probably once every couple of months.
I do keep my iTunes archive in my documents directory so that it gets copied too.
My Seagate external hard drive sits about 3 feet away from the iMac so no physical separation exists......
Most of our photos are either online in albums at places like Photobox or Facebook so we could probably regenrate most of what we would lose. Probably.
Mind you - Having said that, my desk pedestal contains one off paper copies of loads of important paperwork and I don't have copies of any of that either - although things like V5s, MOT certs, Birth/Marriage certificates etc can always be regenerated for a fee.
At the current prices for replacement, I'd say that our 5 passports sitting in the desk drawer would be the most expensive loss! Several hundred quid to replace 5 new passports!
Basically - I wouldnt want a fire in the study!