I myself am doing the same exact thing as you, basically making my subroutines "generic", (at least any subroutine I write that could ever be used again) more for my own code library and the benefit of the practice than a module or anything, but I haven't really taken the approach of using prototypes. At the mention of making my subroutines generic, my guru suggested using them, but upon my own research, I just didn't see the benefit, seems a bit redundant to me, perhaps I'm missing their functionality/purpose?
Also, just food for thought, in doing this I've found it much easier to write a specific one time sub, then go back and change a few var names/etc to make it generic, than to write it generic the very first time through. I always feel a bit guilty about this, because I instinctively sense the waste of time and redundancy of writing something just to re-write it, but once you've got a huge library of very generic subs, it pays for itself many times over, and saves much more time than it wastes, IMHO anyway.
Oh, and JavaFan, very nice, I've never seen that in a sub prototype, ";" meaning an optional second scalar, I was about to suggest to lyapunov to just use an @ as the prototype, as your second example did, when I saw your reply and learned a new solution. ++