The 4.2MB Installshield-based executable SAP provides actually launches a 377KB MSI file which in turn delivers a 56KB executable. If you are in an Active Directory environment where an MSI is preferable or you want to reduce bandwidth during deployment, here's how to get to that MSI...
First, download Filemon from the Sysinternals page on Microsoft's site and launch it. Set the filter to look for "*.msi" files.
Launch the SAP-supplied Service Connector installer and choose a language. Filemon should now be telling you about a "SAP Service Connector.msi" file located in your "C:\Documents and Settings\*\Local Settings\Temp" directory inside a directory with a name like "_is11A". Do not exit the installer yet. Grab that parent directory ("_is11A") and copy it to a safe location on your system. Rename it as appropriate. Now, quit the installer. (It should delete the original "_is11A" directory on its way out.)
Inside you should find several files:
SAP Service Connector.msi
The MSI file in this directory can be launched directly and used to silently install the Service Connector on the PC.