XKCD

For fans of the comics see if you can work out what panels they're from.

I'll start off easy

yay for graph jokes

"I'm not very good at this":

Even I have no idea what this is from (but google found it for me =] )

and a slightly easier one

Links to the comic strips after the jump

http://xkcd.com/150/

http://xkcd.com/231/

http://xkcd.com/159/

http://xkcd.com/520/

http://xkcd.com/556/