Just ran across this gem of an alpha release the other night, and I can't get enough of it. I'm VERY good at orbits, but when it comes to a Mun landing, I fail as bad as a fat kid in a 1 mile race (and I was that fat kid, so don't get offended :P).
It's actually quite a clever piece of software, and very addictive. Would like to see some of it in Outerra, eventually :) (*hint hint Cameni and AngryPig ... orbital mechanics FTW!)
KSP is very addicting:D One thing you should all try is to create the longest possible rockets with fixed wings on the back, and steering wings at the front. You then get a funny looking wiggly rocket that'll eventually break :D
Which brings me to another idea: There are terrain models plus imagery of the Moon and Mars - how about extending Outerra beyond "Terra"? The Moon should be simple - no atmosphere ;-).