When developing .NET applications, particularly Sharepoint applications you might find yourself updating the GAC (Global Assembly Cache) and restarting IIS a lot. This can be time consuming if you are making a lot of short interations in your development cycle. Below are two steps you can take to automate this and minimize your wait time.
First instead of restarting IIS using iisreset, we can restart just the app pool we are working with. Just add the following commands to you pre build event of your project. I add it to the pre-build instead of the post build, because if I attempt to build before restarting the app pool then it will often error complaining that .NET has it locked. In order to give the restart command time to run before the build starts, the next command functions as a wait for 5 seconds.
cscript c:\windows\system32\iisapp.vbs /a "SharePoint - 80" /r
ping -n 5 127.0.0.1 > NUL 2>&1
When needed, I also update my project post build event to add my new dll to the GAC with this command.
gacutil -if "$(TargetPath)"
You can find gacutil.exe under C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322 (you dont have to be using 1.1) and move it to c:\windows\system32 so that it can be found.