I compose music. I have written a couple pieces in dreams, non lucid mind you, that were still in my head when I woke up and I was able to grab an instrument and make a quick recording. One of them is one of the best things I've ever written.

Music is present a lot in my dreams and many times there are songs or instrumental pieces that are entirely original but I can't remember enough of the melody when I'm awake, but the couple times I was able to remember it was pretty good stuff.

I also practiced a new swimming stroke in a dream once and the next time I went to a pool I was able to do it. Mind you, I already knew how to swim by that point, but that was a stroke I hadn't been taught.