I'm sure a lot of you have done this one before:
Moved all sharepoint databases from one db server to another, probably in the process of upgrading from SQL 2005 to SQL 2008 right? Then you realize that you have now lost your central administration site and really have no idea how to get it back so you can change the location of the databases? Yeah…I did it this weekend too.
Luckily, you can run the following command to get your central administraiton site service running on a web front end:
stsadm.exe -o provisionservice -action start -servicetype
Another way of doing it is to remove the web server from the farm, then add it back, selecting the advanced option to make it host the CA web application
This made me very happy that I didn't not have to recreate my Farm simply for the lack of a front end web to change things!