Just found this:
Creating the icon file
You can use any graphics application to create an icon of your choice. The beauty of the icon is that you do not have to think about the glossy finish or the rounded corners, effects which iOS automatically applies.
The only thing you need to consider (apart from the artwork itself) is the size of the icon. As Apple has introduced the iPad and also the more high-res iPhone 4, there are now a variety of icon sizes you can use:
Standard iPhone: 57×57
For the iPad: 72×72
Optimized for iPhone 4: 114×114
So, that means that the 114x114 icon works..... Bruuuuuno!!!!!!!
