Be careful.That kind of attitude will get you a brick in no time. You can install programs from something called extras-testing and extras-devel, but don't just go on there and start installing stuff left and right. Testing and devel releases are unstable and the only reason you are able to install them is so you could report back the bugs you find.

If you install a lot of programs at the same time, it's harder to tell what screwed up your device. Also, unless you know exactly how to reset your N900 when stuff goes wrong, please reconsider installing any of the unstable apps.