Below is a good method for watching dvds but for those unsure about using the terminal here is another method that doesn't use the terminal.
The default media player smplayer, will not play dvds when you connect a external drive because it doesn't have the licensing. Windows media players' license is payed for by microsoft so it doesn't need any extra software.
1. Goto http://download.videolan.org/pub/libdvdcss/1.2.9/ and click on the file that says deb 2005-Jul-11 20:42:40 - Directory 2. This will then prompt you to ask where you want it saved click save to disk then choose somewhere to save it. 3. Open the file manager in the work tab and find the saved file right click and click install DEB File then it will have installed it.
You are now ready to watch dvds on you asus eee pc simply connecy your exteral drive open smplayer and clcik playd dvd from drive. For best playback: in preferences in the output section select xv.
Screenshots: http://eeepc-albkwan.blogspot.com/2009/04/watch-dvd-on-eeepc.html
Many commercial DVD films will not play in SMPlayer via an external DVD drive by default. This is because the Eee PC does not come with the necessary library, but it is easily solved. If you follow the steps below from start to finish, you will install the necessary library without any other change to your system remaining in place:
Ctrl Alt Tsudo nano /etc/apt/sources.listdeb http://www.debian-multimedia.org/ oldstable mainCtrl X, press Y, press Return.sudo apt-get updatesudo apt-get install libdvdcss2Y, press Return.sudo nano /etc/apt/sources.listCtrl X, press Y, press Return.sudo apt-get updateexit
To improve playback, in the Media Player (SMPlayer,) click on Options, then Preferences. In Preferences click the down arrow next to the Video in Output drivers, and change the option to xv.