The short answer is... it doesn't exist yet. Thankfully things are not quite as bad as that.

There are a couple of approaches an ISV can take if you plan to redistribute the .NET Framework AND you can not rely on Internet connectivity to take advantage of the SP1 bootstrap download.

• Option 1: If client machines are Windows Vista, then .NET Framework 3.0 SP1 will be part of Windows Vista SP1 when that ships (currently available as a release candidate on MSDN for subscribers). Probably not that helpful to know - which leads me to...
• Option 2: Redistribute the .NET Framework 3.5 (nearly 200MB) - which includes the .NET Framework 3.0 SP1. Installing 3.5 should have no impact on 3.0 applications - but a spot of regression testing is always a good idea.
• Option 3: Create your own redist using the guidelines posted by Aaron.
• Option 4: Wait a little longer until we release on MSDN an official MSDN deployment and administrator guide.