I have just discovered a conflict between Skype and WampServer that I thought I would share. They both use port 80 which causes the conflict. If you run Skype before running Wamp, then Apache will not run. If you go to a site on localhost, you will probably get a blank screen.
The solution is pretty simple. Just make sure you start all services on WAMP before you open Skype. If Skype is disconnected it will work fine. You can then connect Skype once Wamp is running.
This is a known conflict and has been reported here: http://www.wampserver.com/phorum/read.php?2,36489