I've set up a redbubble.com shop. Mostly for concrete reworkings of tweets, hashtags and discussions.
Both these two re-workings are about the outing on a #NewsLtd newspaper "The Australian" of a pseudonymous blogger Grog's Gamut by it's journalist James Massola. The discussion is best illustrated by this list.
This first one even made it to the main steam media with an article at the Canberra Times.
Also look at Wolfcat's redbubble, who seems to have more time for it than me.
And yes, I've sold several now. Hooray! But I wish TShirts were clickable, I guess they will be soon.