Skype Hacks: Tweak Skype by Editing config.xml
Source: O'Reilly Media
Hacking around with Skype's config.xml file can cause problems, especially if the user tinkers with settings not discussed in this paper. Skype, however, has the ability to rebuild a default - but valid - config.xml file when it encounters a problem with the existing config.xml file. This is the case even if the user renames or deletes config.xml - Skype simply builds a new one. Under such circumstances, Skype tries to restore as many of the personal settings and preferences in the new config.xml as possible, but it's always wise to make a backup of the current config.xml before one makes any changes.