Spidy,
use 5.008008; Why?

As has been mentioned by others, there are a few modules that perform a similar function. When I was playing with this idea (see RFC: Seconds2English for details), it was a toy project to learn. I do remember adding features that were not in any of the CPAN modules available at the time, but now I don't remember what they are. Here is my recommendation:

Find one or more features not provided by the existing modules and provide a patch to the author. If the author is unreceptive and the module is OO, then subclass and post on CPAN. If the module is not OO and you feel these features still warrant addition to CPAN, then put up your own module but be sure to include in the POD the distinction between the modules so that folks can choose for themselves.