Well, if you thought that smartphones need to have a large screen in order to enjoy the multimedia capabilities to the fullest or if you need to see a lot of information simultaneously, you will have to think again. This is because Sony Ericsson doesn’t agree with this and has launched the Xperia X10 mini. It is compact phone and is smaller than a credit card.
It is 16mm thick and even though it will not fit into a wallet, but will surely fit in any pocket. Its 88gm weight makes it almost unnoticeable. So, I guess this phone might bring back the concept of ‘small is big’. 
It has 240×320 pixels in 2.55 inches, which makes it a little difficult to surf. The capacitive screen makes scrolling very efficient; although for those who are used to a large screen might find it a little uncomfortable initially but it is a matter of time before you get used to it.
The major drawback in this phone is that it doesn’t support Flash. Another thing that might seem like a problem is that the screen is too small to accommodate a QWERTY keyboard. However, Sony Ericsson has done well to have a separate slide screen for the keyboard.
The camera is pretty handy with a 5 mp lens and auto focus. There is an option for a quick launch and it is very easy to use. Again, the small screen causes some problems as your fingers might stray all over. On the other hand, the sound quality is good as well.

I agree, a great phone. There is an update to the operating system on this phone. Android 2.1 is available free. I think you need to check with your Network for a download.