In order to make offline software installation even more available and easy, I've written a small vb.NET program that interprets and downloads .deb or .rpm packages in Windows.
Running this program requires vb.NET framework on the Windows PC, but that pretty much comes standard any more. And I'm going to work at porting it to C, so that it will run on any Windows machine, vb.NET or not.
I have a tutorial on the Ubuntu forums on how to use it, and the same procedure should (mostly) work for RPM based distros as well.
Link here.
You can download the program from
Sourceforge. There's a zipped .exe available, and also the source code as a .txt file, if you prefer to compile it yourself.