Installing IIS on Win Server 2003 without the installation CD?

There is no standalone installer - you will need the files from the installation CD. As GateKiller pointed out, they can be on the network or a drive, but without the Installation CD, you have a problem.

My only suggestion: Try the Trial Version ISO, but that is at your own risk:

http://technet.microsoft.com/en-us/windowsserver/bb430831.aspx

And when you are prompted for the file location you can point to the equivalent file on another server that already has IIS on it

\\myotherserver\c$\windows\system32\ and so on

While using add/remove windows components, the dialog should ask you the location of the files which you could enter a location on the local disk or network location.