Macbook starting problem

Hello !
I bought a white Macbook 3 weeks ago. Everything was going well until 2 days ago, when I turned it on. It started up normally, taking slightly longer then usual but otherwise OK. It showed the desktop , I could move my mouse but I couldn't click on anything. My keyboard didn't work either. I rebooted it a couple times, but it did the same thing every time. I decided to leave it sit for a while and after 30 minutes, it started working normally again. But every time I open it again, it does the same thing. Does anyone have a similar problem? How can I fix it? If I can't find a solution, I will exchange it for a new one, but if I can repair it otherwise please tell me...
Thanks !

That machine is too new to have those kind of problems. There is no point resolving something like that yourself. Take it back to your local Apple store or reseller and let them deal with it under the warranty.