Is this module really necessary? It's a wrapper for unpack() calls. Worse, it has an object-oriented interface when function calls will do, so there's extra overhead that is not needed. Every conversion function is loaded into memory even if it's not used. (Though the functions seem too simple to justify the AutoLoader.)
Also: the translation to/from binary do not take endianness issues into account (sometimes one needs to explicitly use little-endian).
I would defend the idea of provided simple and commonly-used functions in a module just to save one from having to re-write the same few lines of code each time, but there should be _some_ extra functionality to justify this.