We're in the midst of upgrade from BizTalk 2006 R2 to 2009 at my customer. In this environment, only the developers' workstations have internet access, so to install BizTalk 2009 on the servers, I have to download the redistributable CAB files manually, save them to a network share and specify their location during the upgrade process.
The problem with this is that the installation guides for BizTalk 2009 only link to the 32-bit and 64-bit versions of the CAB files for Windows Server 2008 (even the "Installing BizTalk Server 2009 on Windows 2003" guide). In actuality there are 8 different CAB files, 2 each (32 and 64 bit) for XP, Windows 2003, Vista, and Server 2008. Adding to the confusion is that the CAB files are named the same between the BizTalk versions, so the CAB file for Windows Server 2003 X64 is named BTSRedistW2K3EN64.cab for both the 2006 R2 and 2009 versions of BizTalk. As the installer package automatically picks the correct CAB file download location based on your operating system version, you'd either have to 1) Find one of each type of OS for your environment which has internet connectivity and have the installer pull the correct CAB down for you or 2) figure out the links for each operation system version and pull down what I need. I opted for the latter.
You can find the correct links to download these CAB files inside the Setup.xml and Setup64.xml documents inside the MSI folder in the BizTalk 2009 setup installation media under the PlatformComponents->RedistCAB element. If you need the redistributable CAB files for 2006 R2, the same holds true there.
To hopefully save folks time though, I'll list out the CAB links here:
BizTalk 2006 R2