That is an excellent idea.
Having an off-site backup of important computer files is a good idea and one that many companies use in case of fire, burglary, flood etc.
Mind you, I have 18 CDs of digital photgraphs, plus my daughter has another 10 CDs worth, plus I have about 20 or so other backups on CDs and DVDs.
That is an awful lot of CD & DVDs to copy.
I suppose another solution is to buy a external hard drive (only about �25 for the actual disk) and copy all your files to that, then take the hard disk to a relatives house.