So I am learning Ruby on Rails (and absolutely love it by the way) and decided that I wanted to try and get my rails application running on my Fedora 8 VMware Fusion image. As with everyone else the first problem I encountered when trying to access the application on any other machine on the network I hit problems with SELinux not allowing access. Here is the work around that has worked for me.
Open a terminal in Fedora and type
# system-config-securitylevel
This will open the configuration application for SELinux. Now change to the other ports tab and click the ‘Add’ button. Look down for the relevant port number on the list, most likely 3000 and add it. You should now have something along the lines of the image below

Fire up WEBrick and try accessing via another machine on the network and everything should work just fine, at least it did for me.
Back to my learning Rails