they say upnp is dangerous, but I like it since it allowes programs like torrent clients, msn, xfire and other things to configure the router easily for optimal performance
now... sometimes you want to remove some settings, because they aren't nice. I found a tool for it a while ago, for windows xp and vista.
you can even add rules yourself, for quick portforwarding
because it's on codeproject.com and you need to sign in for it... I kinda repacked it, so not everyone has to create just another account
this is the website: http://www.codeproject.com/KB/IP/PortForward.aspx
the attached zip in this post contains the "demo" file... it still pops up some screens explaining things... maybe I recompile it later and remove those, but have fun for now
don't forget to completely unzip it somewhere on your harddrive, or just double click the executable in winrar.
for mac users this thing should work: http://www.codingmonkeys.de/portmap/index.html
never tried it out tho...