I have just finished the development of a web service application in visual studio.
Is there an easy way to wrap it in an installer, so that I can just ship it off to technical support, and they can have a wizard based installer that will fully setup an IIS site for them, either in 6 or 7?
You can use Visual Studio's built in setup project. I've only tried this once on a test project, but it created all the necessary stuff in IIS 6 just fine.
I would suggest you export the IIS METABASE for your local instance of the service and then this can be imported into a new server to create the correct IIS configuration. Have a look at Copying IIS Configurations using iiscnfg.vbs The METABASE is just an XML file and you will easily see the specific values that allows you to edit them should the deployment be different in anyway.