Bret Victor's Magic Ink essay galvanised me in to pursuing UXD as a career. For my Fate prototype, I tried out his natural language concept for setting a new filter. It was quite fiddly to do but I really think it's a much smoother experience than conventional input methods.
Summary: I wanted to try OmniGraffle but had a PC. I used a virtual machine to run Mac OS X on my laptop and install OmniGraffle. On balance it was worth the slight headaches, and I list my steps here as a guide for others.