You can thank you're provider and cell phone manufacturer for the restriction.
I just got a Samsung Fascinate yesterday and found Can Knockdown, google earth, and a whole bunch of other apps can not be installed.
And before any of these morons chime in with, googe earth works-it doesn't. It's a restricted app on the market now and can not be accessed. Period.
I am devastated that this is the phone I'm stuck with now. When I get the money I'm going to just leave Verizon entirely. Their service isn't even reliable, now their phone are crap.