you can indeed launch urls from a projector provided you have a browser installed.
(these can be local or live depending on your user having a connection or not)

if you attach a get url command to a button it will launch it in a browser window--in relation to your other post....you could have a projector that launched a subsequent .swf in a browser window so that your presentation continues to play in a netscape/ie window

as i said before there are many ways to do this depending on your end use.