That's funny! I had a Yamaha PSR-E303 for two years.
I'm not sure how to get it to record yet, but I can at least tell you what I'm working on. You may recognize it, you may not.
I'm playing a theme and variations piece by Dmitri Kabalevsky, that really annoying Clementi sonata that everyone plays, and a really cool piece with a 7/8 time signature.
Plus a song from Final Fantasy VII. Never got through the game, but I loved Aerith's Theme.

Congrats on the K2000. I'm sort of into synthesizers too, but unfortunately I had to choose between a synth and a digital piano... And I really need the weighted keys.