I've sent a friend request to someone I'm already friends with ...

[AuroraAlfresco]

... except I didn't - absolutely not. He showed me it on his phone and there's the option to "Confirm" or "Ignore" ... he's not clicking confirm in case it's something dodgy, but it's my profile pic up there! We've been friends for a couple of years and I definitely haven't accidentally defriended him, nor sent this new request; we're still showing as friends on my FB. How can this be??

Its dodgey, people are doing this using your profile name and pic to gain acess to your friends list. I'd send a warning to your friends that you only have one profile.

*dodgy

Facebook cloning does happen, apparently: Snopes report - people take your name and profile pic to create a new account and target your friends. Might be worth warning others on your friends list.

Really, Chao?? Has this happened to you? Why would they do this - what's in it for them??

Some of my friends were sending warnings around about it on fb. Dont know what they get from it, apart from spamming your friends with all sorts in your name, which is really rubbish in itself.

look

and here

Send a warning to your friends. You dont want their profiles spammed with porn under your name.