Deja Vu! I am sure I have posted this somewhere else on YD today.....
Bought my kids one of these for Christmas....
http://www.gwaytech.com.tw/ not only does it play mp3s and have 20gb of disk space it also plays mpeg4 movies ie divx or avi. Thus you can compress your favourite dvds and take them with you when you travel. At the moment my youngest has 10 dvds and 15 music cds on his gadget and still has over half the disk space left.
Costs around £230 but comes with rf car adapter and leather case....worth a look.