Yes, below is a general method that will work give or take a few minor adjustments. You are basically ripping the contents of the CD as an image file (rather than copying each file). The end result is one file (normally .iso file) which is one large file that can be thought of as a backup of your CD. In principle, there's nothing illegal about doing this if you own the original.
1.) Find a program that will convert your CD into .iso format and download it. There's loads, I recommend CDBurnerXP (it works on Windows 7 too)
2.) Stick in your CD, and produce the .iso file, saving it to your hard drive.
3.) Copy the .iso to your USB key
4.) Download and install a utility that will mount this .iso file as a 'Virtual CD-ROM drive' - I recommend http://static.slysoft.com/SetupVirtualCloneDrive.exe
5.) Keep a copy of the above utility on the USB key too (incase you dont have access to the Internet from the next PC you use it within)
6.) Learn how to use and mount the .iso file as a virtual CD-ROM drive on various computers. The above utility does it all for you with minimal fuss.
I preach the above method to all my colleagues and would recommend it to all on here. It's very unwise to carry around your most treasured learning material on CDs that scratch very easily. I've even come across guys who despite having a laptop and tablet PC insist on accessing all company docs from CDs