Self-Signed CA

Firefox
Just import it

Windows
How to make IE8 trust a self-signed certificate in 20 irritating steps
 * Source: http://stackoverflow.com/questions/681695/what-do-i-need-to-do-to-get-internet-explorer-8-to-accept-a-self-signed-certific
 * 1) Browse to the site whose certificate you want to trust.
 * 2) When told "There is a problem with this website's security certificate.", choose "Continue to this website (not recommended)."
 * 3) Select Tools->Internet Options.
 * 4) Select Security->Trusted sites->Sites.
 * 5) Confirm the URL matches, and click "Add" then "Close".
 * 6) Close the "Internet Options" dialog box with either "OK" or "Cancel".
 * 7) Refresh the current page.
 * 8) When told "There is a problem with this website's security certificate.", choose "Continue to this website (not recommended)."
 * 9) Click on "Certificate Error" at the right of the address bar and select "View certificates".
 * 10) Click on "Install Certificate...", then in the wizard, click "Next".
 * 11) On the next page select "Place all certificates in the following store".
 * 12) Click "Browse", select "Trusted Root Certification Authorities", and click "OK".
 * 13) Back in the wizard, click "Next", then "Finish".
 * 14) If you get a "Security Warning" message box, click "Yes".
 * 15) Dismiss the message box with "OK".
 * 16) Select Tools->Internet Options.
 * 17) Select Security->Trusted sites->Sites.
 * 18) Select the URL you just added, click "Remove", then "Close".
 * 19) Now shut down all running instances of IE, and start up IE again.
 * 20) The site's certificate should now be trusted.

Thunderbird

 * 1) Click Tools-> Options
 * 2) Select the Certificates tab
 * 3) Click 'View Certificates'
 * 4) Click 'Add Exception'
 * 5) in Location, add 'https://yourvoip.example.com'
 * 6) click Get Certificate
 * 7) click Confirm Security Exception