Question : How many types of mobile OS and browsers?

I build a website which needs to support mobile phone to browse it through mobile browser.

However, how many types of os and browsers for mobile phone.

So far as I know,
windows mobile, mobile IE
iphone, safari
samsung, dolphin
symbian, opera
palm, ?

any others?

And, there are so many mobile devices with various OS and browsers.

Is there any ways to test among them in an efficient way?

Answer : How many types of mobile OS and browsers?

I'll look around for testing mobile browsers, but here is a great way to test desktop browsers:
http://browsershots.org/