100GB on recordable CD's! Yeeouch! I wouldn't burn CDs for 100GB of data. You're talking about around 150 CDs at 700MB / ea.
If the server isn't too old to have USB 2.0 ports, stick an external hard disk with a USB interface on it and copy the files that way. You might mention the operating system on the server computer. That would tell us if things like USB are available... (i.e. if it's Windows NT 4.0, for example, USB is a no-go).
It's likely the server has an Ethernet connection. Carry in your laptop and either a small Ethernet switch or a crossover cable and setup a little network between your laptop and the server. Just statically assign IP addresses to both machines and use the native file-and-print sharing tools on the machines to copy the files over. Of course, if you don't have 100GB of disk on your laptop, bring an external disk for the laptop, too. (Again, knowing about the operating system here would help...)