What's up with the # symbol before words?

[Amber-jason]

I'm sorry I'm a little behind on the media thing since I've been living a pretty busy life lately! But lately I've been seeing people post on Facebook and blogs "#......" (replace the periods with words). I'm at a total loss. What the hell does that mean? Lol I don't understand the significance. Who invented this trend and why does everyone use it? Thanks.

[Helpful Troll]

what #are #you #talking #about? #what #symbol?

[SÃ mhach]

It's to indicate the #topicofconversation. I think it took off with the advent of Twitter, but I don't know from where.

[Presidentt]

It's actually used on twitter to create a hashtag, a link to connect what everyone is saying about that particular subject.

Example,

I am so hungry! #TeamNoFood!
That phrase follwed by the '#' would create a link, and you can click on it to see what other people are saying about being on #TeamNoFood

Haha, people use it on facebook to taunt people without Twitter accounts.