In a word "yes".
Keep in mind that all port forwarding does is maps a WAN port to a LAN port. It is then up to you to make sure that firewall software, local to that machine, is not blocking traffic and the web server is configured to answer requests from the outside world.
[ That concludes the pre-amble ]
Now we come to your specific configuration. From your description it sounds like you have a Linksys
router w/wireless capability. What model is it and how is it connected to your network? The differing IP addresses you mention leads me to believe that you have enabled the connection sharing on both SpeedTouch and LinkSys. Is this assumption correct?