If you have ever had to walk around a room or building with a CD or flash drive in order to install something, then you need to try this. I tested Doppelganger by installing three Office 2004 (11.3.7, 11.3.8, 11.3.9) updates in a lab of 30 eMacs, and it worked flawlessly. It took me about 15 minutes to create the package, but now that I've done it, future packages will go much quicker. If you only install Apple updates, then this program is probably unnecessary, because they already distribute their updates as .pkg files. However, if you want to install Office updates, printer drivers or anything else that doesn't come as packages, then you need Doppelganger! I use Apple Remote Desktop to distribute packages, so if you don't have that, you will still have to walk around and install your packages, but it will still help by allowing you to customize the installation (registration, prefs, etc.)