And if you place a group of links in a bookmark folder--the last option is "open in tabs" option... It works great. Even on dial-up I open 10 different web sites at once.
Also, somebody may have a better suggestion, but I found that FireFox did not seem to support TABBED BROWSING as a default setup. I loaded an extension named TabBrowser Preferences v1.2.4--It made my tabbed browsing operations (such as a open new window link will open in a tab instead).
-Bill