The solution comes from Paul Kretek's website where he outlines how to use FastScripts to assign keyboard shortcuts to specific tabs. Paul and Steve both want to use Safari, but they like Firefox's method of numbering tabs 1-9 used together with the command (⌘) key . By default, Safari uses ⌘+[1-9] to jump to bookmarks on your bookmark bar, which I use all of the time so I'm planning to make keyboard shortcuts for tabs control+1-9 instead. (⌘+0 [zero] is used to set the zoom back to original size.)
Who knows, I might change my mind. I had found myself trying to use ⌘+[1-9] for tab switching in Safari because I was already used to tab switching that way in iTerm. The only bookmark keyboard short I use with any frequency is ⌘+1 which I use to invoke Quix which I've written about previously and absolutely cannot work without.
Paul's instructions are very thorough, and although they may look a little complicated, it's something you only need to setup once. Also note that FastScripts is free for up to 10 shortcuts, after that it's US$14.95 for unlimited use.