I would defiantly like to do a t-shirt, most likely in the colour yellow. I had bought a Los Pollos Hermano shirt a few months back and I was very disappointed in the quality of the shirt. This is the photo that they had used,
http://ih1.redbubble.net/work.7334671.1.fc,550x550,navy.v3.jpg As you can see, the logo is blurry in that photo. Now imagine the same image being enlarged even more for the shirt, I was not impressed at all. I am pretty sure that the image I have been working on should look great on a shirt. I think your absolutely right about wrapping it around a cup. I just did a quick search and I found all of the sites I visited have a very large minimum order. They may have even done the same thing for the cup that was used on the show or I suppose it is possible that they ordered a lot of them and used them for cast and crew events. Either way, I think the only option is to make our own.
http://img695.imageshack.us/img695/5856/lospolloscup.jpg Great idea about Tuco's grill in the block. I was actually thinking about that awhile ago but I had forgotten about it.