If you are like me, you may find yourself constantly creating site collections manually to test and retest something or other, and scripting the site collection creation doesnt always make sense - depending on what you are testing.
Today I got tired of entering the user name over and over again in the site collection administrator box - it is always the name of my user - which is the only user in my domain as it is a stand along development box. So...I hacked the page for site collection so it would have a default and I won't have to worry about it. Note that this should only be done in development boxes, and at your own risk.
My solution was to edit the built-in "createsite.aspx" file, sitting at "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\ADMIN\createsite.aspx". In that file I located the "PeopleEditor" control with ID "PickerOwner" and added CommaSeparatedAccounts="mydomain\ishai". Save, and done!