The fused extension cord is an interesting concept. As most of you know, the standard plug here in the U.K. contains a cartridge fuse, so any extension cord fitted with this plug automatically has fuse protection at a maximum of 13A.
It's still not foolproof though. Some smaller-gauge extensions will come with instructions that a fuse no greater than 5A must be used, but people will still fit a 13A fuse and then wonder why a 3kW load starts burning up the cord.
Code requirements to insure an ample quantity of suitably placed receptacles etc. certainly go some way to reducing misuse of extension cords, but I think that ultimately it has to come down to educating users in their correct use.
And whatever the NEC or some other NFPA rules or their equivalent in other countries say, most people aren't even aware of the existence of such rules, certainly couldn't care less about abiding by them, and will just plug in whatever they have to hand.
How to get the message across is another matter.
