Android developement - first try

I recently purchased a HTC Desire which basically is my first foray into the new generation of smart phones.


I wanted to try some development so I downloaded the SDK and the other bits and piece described here http://developer.android.com/guide/developing/eclipse-adt.html.


The java development part was fairly straight forward, however the layout and how to get that right, that seems a bit harder. Probably something that I am missing.


Anyway my first application is a reverse calculator.

This visualizes the operands as small blue dots and then allows you to pick a choice for the answer.


I would like it to be centered in the screen like this

This has however had me running in circles until now, spending at least 5 hours trying to get this right. I have tried RelativeLayouts, LinearLayouts & TableLayouts. 


I have done a few applications for windows mobile and I must admit that I found layout easier to do in visual Studio.