It means that you are just a dense appliance to be used by someone of skill and then put away until needed again. Like a fleshlight.
No, no, like what goes into a fleshlight.
So when you call someone a tool you are actually channeling Shakespeare.Using tool as a slang term is not, however, a modern Princeton invention. Tool is a word with a long history. By the 1660s, a "tool" had come to mean a person who is easily manipulated. "Which made some take him as a tool, That knaves do work with, call'd a fool," wrote Samuel Butler in 1663. An 1849 text about the history of England describes sheriffs as "tools of the government." Across the pond, in a similar vein, when the Female Labor Reform Association at Massachusetts textile mills went on strike in 1845, its resolution described the chairman as "merely a corporation machine, or tool." Perhaps this usage relates to another slang definition of the word: For centuries, "tool" has been used to mean "penis." In "Henry VIII," Shakespeare describes a foreigner who comes to the court as someone "with the great Toole."

paging ns1...paging ns1
Oh wait...not the band?
Nevermind ns1. Go back to googling snorgi pics.
Tool - Sober: http://www.youtube.com/watch?v=hglVqACd1C8
I seem to recall using the word 'tool' to describe tool like people before the internet, in HS. Don't think it is an internet/forum specific label. Someone who is a tool is not the same as a fool, but one can be both of course, and usually are. But, they have different connotations and are not directly interchangeable.
THIS
Tool is a very old term. It just means that someone is behaving in such a way that they are not able to change their focus to soemthing else. Usually in regarsd to doing something nerdy like fixing a Guitar. Roommate being fixated on fixing guiter for 2 hours. It's Friday and room mates are waiting for him to finish up so they can go out. You would tell the guitar man "Stop being such a tool". Inferring that he is litterally a tool that is serving a specific utility at the time.
