You can download the update.zip using any computer by following the instructions here:
https://www.entourageedge.com/suppor...barticleid=236.
Note that this will give you the latest Dingo version.
To get the Ermine beta (which includes Android 2.2, aka Froyo), you need internet connectivity on your eDGe. If wifi doesn't work, then a USB-to-Ethernet connector will work. It needs to be a "StarTech USB2106S" adapter, like this:
http://www.amazon.com/USB-2-0-To-Eth...2106794&sr=8-1.