For those of us who have the good fortune of deploying SQL 2005 into the OpsMgr environment they are also building...I wanted to draw your attention to this KB Article. Probably old news, but proved very relevant for me recently.
During the installation of SQL 2005, installation may hang when the message"Installing Local Groups" is displayed. In my particular instance, the cause was "the primary domain had many external trust relationships with other domains or many lookups were performed at the same time, the time that is required to look up domain group names may increase significantly. Therefore, the time that is required to install SQL Server 2005 may increase."
The resolution, disconnect the network card! I tried several other possible solutions which chewed up a few ours. With no success, I opted for the original resolution, I disconnected the network card and installed from the console. Success. Applied the same procedure to the Reporting Server. Just wanted to share this in case anyone lands in the same situation. Lesson learned: Just have the client ensure SQL is installed prior to your arrival on-site 🙂