Any tips or links on being more sociable?

I tend a be a lonely person and I'd like to change that, and I'm told that what I need is people.

I like chatting and all but I tend to loose interest and go cold for days, and I get the feeling people loose interest in me because I disappear for long periods, I'n which I just retreat to the quite of the things I like doing, like drawing, animation and such.

Anyways, I want to get more involved but don't know how to motivate myself, and simply saying I want to get out there is just not cutting it. So if anyone has something for me I'd greatly appreciate it.

I don't want to be a lonely 17 year old.