How can I install Skype in Knoppix?

[Capricorny]

Skype is a rather proprietary thing, and there are free alternatives. From the Debian wiki page about Skype, see http://wiki.debian.org/skype:

Skype is a non-free (proprietary) software. It isn't supported by Debian. It's probably wiser to use a VoIP software, like ekiga , linphone or jitsi !

Then the wiki page goes on to explain how to install from Skype's repository. Add the correct deb reference to /etc/apt/sources.list:

deb http://download.skype.com/linux/repos/debian/ stable non-free

Then proceed as with any other CLI package install:

sudo apt-get update 
sudo apt-get install skype

I just tried it, got this result:

#>sudo apt-get install skype
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  skype
0 upgraded, 1 newly installed, 0 to remove and 1019 not upgraded.
Need to get 20.2 MB of archives.
After this operation, 26.2 MB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  skype
Install these packages without verification [y/N]? y
Get:1 http://download.skype.com/linux/repos/debian/ stable/non-free skype i386 2.1.0.81-1 [20.2 MB]
Fetched 20.2 MB in 29s (694 kB/s)                                                             
Selecting previously unselected package skype.
(Reading database ... 364610 files and directories currently installed.)
Unpacking skype (from .../skype_2.1.0.81-1_i386.deb) ...
Processing triggers for gnome-menus ...
Processing triggers for desktop-file-utils ...
Setting up skype (2.1.0.81-1) ...
#>

I remember when doing something similar two years ago, that there were quite a few glitches when running Skype then. Haven't tried now. Beware that the 32-bits version should be used to minimize problems.
BTW, ekiga and linphone are present already, so Skype should not be desperately needed. Anyone having bad experiences with them?