As you can see from the discussion so far, there are some people who are for the S2 and some who are for the FZ5.
I was looking at both of these as well a few others in the super zoom class, and personally I think there is really very little difference between the 2 in terms of final picture quality, especially if most of the time you are printing 4R size.
In my opinion, only a couple of stand out differences.
The S2 feels a little more solid, and has a flip out and twist screen
The FZ5 is lighter (Means you are more likely to carry it around), and it is easier to use, especially if you have not used a Cannon camera before, more idiot-proof.
As a lot of people have mentioned, pick both up, see which feels more comfortable in your hands, and which one you find the easiest to navigate through its functions.
Regardless which one you chose, I think that you will get a lot of satisfaction from either of these cameras.
Good luck in your selection.