I love the print on this tshirt from Threadless, even if my brain is screaming "what's keeping those balloons up in the air?".
I'm going to pretend I know nothing about the laws of physics. Which actually is not entirely untrue - Physics was never my strongest subject at school. Here's a close-up of the design:
It's currently on sale on Threadless too (US$10 for the girlie tee, and US$15 for the girlie boat neck tee), so laws of physics be damned!