Here's a really cool mashup t-shirt called "Racket Shot First." It delightfully combines Guardians of the Galaxy with Star Wars by appropriately turning Rocket Raccoon into Han Solo. I think these two universes would actually work really well together. Disney owns both of them... I bet they could make a crossover movie or series work if they really wanted too.

The design was created by cs3ink, and you can purchase it here if you're interested.