Well, since I actually work in print, I've got all the connections to feasably get my stuff professionally printed if I wanted to. Its the cost that is kinda annoying. If you only want to print a few things, it will cost you a fortune. But the more you print the cheaper it gets.
I have a cafepress shop.. from like.. long time ago before they started all this charging crap.

I might have to order something just to get rid of my like 5$ worth of credit and close the damn thing.
I've gone all hardcore and aquired a 4 color silkscreen press of the professional variety to do my own shirts. And yes, I know how and have all the shit to make them. Go me.
The only think I don't have any way to do well at the moment is posters. If I wanted to have them professionally done I'd have to order 100 or more to make it affordable. I doubt I could sell 100 posters. Thats where the print on demand thing is neat. But the cost to profit, is as was stated, pitance.
I've seen cafepress' stuff. Its crap. I know there actually is a company local to me ( well relatively local.

) that does comic printing on demand at something like 1.70$ a book ( 22 bw pages w/color covers). Mind you they have a heafty setup cost. The quality however is extremely good. If it wasn't for the major setup cost, I'd probably be with them right now.
Anyway, random rantage.