Like everyone else here, I love mezzi's tute on making t shirt hoodies.
If you don't know what I'm talking about, please go here - http://www.craftster.org/forum/index.php?topic=100217.0
Seriously, it's awesome.
Here's a few that I made:
Made from a too-small dexter t shirt that I got for free (it was a small, I'm more of medium or large). I added red side panels, long red sleeves and a red hood all cut out of plain red t shirts and scraps from other projects. I then made one for my BF as well which is almost identical to this one except it's bigger and has a kangaroo pocket. No pics of that one tho.
Made from a too-big thrifted t shirt with a pic of thailand's floating market. I thought it was cool (it was also brand new and 99 cents - can't pass that up) and I had a surplus of these spring green t shirts (I love it when Michael's has the 5 for $10 deal).
This one I made for my BF. It was a size L Bruce lee t shirt that I got somewhere on sale over a year ago. He prefers an XL or bigger so I added side panels, sleeves and a hood from plain black t shirts the same way I did with the dexter hoodie. It's pretty awesome.
IMPORTANT HELPFUL TIP: I cut the sleeves, side panels and hoods out of plain t shirts so that the open edge (the edge you would normally hafta hem) is lined up with the already hemmed part of the t shirt. Maybe I'm just lazy, maybe I'm a genious.
I've made many many more from thrifted tees, just have to get pics of them. Maybe next I'll do some with zippers or slap some zippers in these.
Thanks for looking!