I noticed the problem with the intermixed POD as soon as I put it in the PerlMonks text box. It's very easy to distinguish POD when you're looking at it with a syntax-highlighting text editor, but in plain black and white, it's much more difficult. This is a drawback to POD I hadn't thought about before, which is too bad, because I find keeping the documentation with the method/function to be very handy. Javadoc commenting gets around this problem by putting comment chars. on every line of the documentation comment; it's a pity that POD doesn't do the same. At least, I can't think of any non-cumbersome way to do this.
Well, now I know why just about everybody else puts their POD at the beginning or end of the module.
Thanks for the comments re: open(). Now that I think about it, the module should handle data passed in as arrayrefs. as well as text files; I'll have to think about this a little more. (And yes, top-level "Gstat::" won't fly.)