Being a bit of a physics geek, I thought of a nice (imho!) t-shirt design, based on the standard model of particle physics (which basically shows all of the fundamental particles so far discovered). I added in the Higgs boson which may or may not be discovered by the LHC in the near future.
So I designed it - and now you can buy it (in a variety of colours of course)! Well, I expect I'll probably be the only one to do that but still... :)