Ever since I started knitting, there's been all these goofy ideas I had about knitting-related designs that I could apply to T-shirts, mugs, etc. Now it's come to fruition: http://www.zazzle.com/stephhw
I have some more geeky ideas, but these are the first four. I believe they are for the true knitting afficianados, no generic "I Love Knitting" here, I tell you what.

"Rip It Good" - ripping refers to when you have to "rip" out your stitches because you have to start over--major suckage.
I bet aliens knit too, and when they visit, they'd say "Take me to your knitters"

