Boy was I wrong! I added the 2nd monitor 3 days ago and I'm amazed how useful it is.
Didn't have to spend any money either which is nice. Had an 14" from an old computer laying around and it took about 5 minutes to add it. Even though it's much small than my main 24" monitor I've seen a big decrease in the amount of time going from program to program, mouse clicking etc. and a nice increase in what I've been able to done.
So for any of you who haven't taken the plunge. Jump in the waters great.