I was just reading The Mental Masochists blog and stumbled across an amazing little prank he pulled... I've never put in this much effort to troll someone, but he did look as though he deserved it, so I'll give him that ;).
I hope you don't mind me linking you here Maso, if anything I'd probably say your glad.
Share any similar stories in the comments, links if you can! I've read some amazing stories like this where people have gone above and beyond extreme lengths to troll, so I'm sure you have some to share.