Hi Janine,
Sounds very useful!
I'll second what Tom said about the importance of the script stopping on error. We don't want the user to wait on the whole install process only to find out that the script bombed in step one. Also makes it easier to find the source of the error if it is the last line. :)
When you get to the point of having something ready to test, I can volunteer a fleet of disposable RH7, RH9, and Debian vservers ready to be messed up and deleted. Takes me about 10 minutes (two command lines and some waiting) to spawn a vserver, and it can be totally goofed up by shell scripts run amok without any problems. :)
