Today I downloaded the 30 day trial of a writing program called Mellel. It's a word processor designed for "creative and technical writing." It looks pretty neat (and much more Mac-centric than Word can ever hope to be.) But...
Every couple of hours an annoying reminder keeps popping up telling me that I'm using a trial version and that I should pay up to use the product.
Every two hours or so. (I've not timed it, though.)