OK, been working in Math::Vector and Math::Vector::Vector3D and it's almost ready to submit to CPAN.
I've sent an RFC to comp.lang.perl.modules to know the opinion of people about it... I've checked there's a Bit::Vector package, but it seems overkilling to me for what I wanted to implement, a metric space through a vector space and a norm (R^n). I'll wait and see how people respond to it. I wanted to reuse Math::Polynomial, a very nicely written package, but there were too many 'dangerous' functions to disable or modify, and so I started it from scratch...
Vector3D provides vector cross product in R^3, which will be useful for Fleet to make the physics of movement for ships and missiles and "slow" proton beams (laser and electron beams move at light speed).
Not much more hacking, as I was working on the self-defense sprays article for JNC. I'm almost ready for another submission, hopefully almost the last one... :-)