In IIS6 on Windows Server 2003, we could recyle the application pool that hosted our SharePoint site in order to force the web application to perform a JIT compile. This would then reload any DLLs it required. This saved a considerable amount of time over an IISRESET.
That command is:
C:\windows\system32\IISApp.vbs /a "SP Site App Pool" /r
(Note that the [...]