I just installed Skype on my new Dell Mini 9n running Dell's Ubuntu 8.04. The installation worked great and I could immediatetly make a test call using the internal speakers and microphone, which is the 'Default device' in the Sound Devices Skype options. You can get to that menu by clicking on the little blue 'S' icon in the lower left corner.
That wasn't the case when I installed Ubuntu 8.10 on my Dell Latitude D600 laptop. I kept getting errors saying 'Problem with audio capture' To fix that problem I had to uninstall pulseaudio and install esound instead, by using the troubleshooting instructions in this link:
Even after that, I could not do a test call with the default device. I tried using a USB Skype phone and it worked ok, after selecting the USB device in the Options/Sound Devices menu. The only problem was that I had to go to Options/Sound Devices every time I plugged in the USB Skype Phone. It's was no big deal for me, but some users may be confused by that. Just wanted to pass this in, in case it helps.
By the way, I find that audio quality is much better if you use a USB Skype phone instead of the internal speakers and microphone on most laptops. Using a separate microphone helps a bit. I mostly make international calls and the the people I call can hear me a lot better when I use the USB phone.
Also note that the keypad on Skype phones does not work by default. You need to install additional software for that. I just use the keypad on the screen and dial with the mouse, then talk into the Skype phone. I can't remember the name of the software, but I installed it on a PC and a Mac and it worked ok. I'm not sure if it's avaialble for Linux. On the Mac, I uninstalled it because I got tired of the popup messages every time I rebooted. Dialing using the mouse on the screen works good enough for me.
Here is an update to my previous post. When I installed Skype, I had been using my Mini 9 for about a week. The computer had a chance ot run the Update Manager and all updates were up to date. Today I tried reinstalling my operating system from the Dell recovery disc. The installation was smooth and straightforward after I borrowed my neighbor's USB CDROM drive. After reinstalling my system, I tried to reinstall Skype. I got an error message saying that 'i386' was the wrong platform. I checked the Update Manager and the last update was 168 days ago, probably the date the recovery disc was made. I clicked on Check for Updates and waited. It took over an hour to get all of the updates. At the end I was asked to reboot. I tried installing Skype again after the reboot. This time Skype installed just fine and I was able to make a test call again.
I want to pass this on too. Make sure to run Update Manager and get all of the latest updates BEFORE you try to install Skype.