Feedback on my first gem: United Attributes

I don't know if this is appropriate for this forum, so please kindly dicipline me, if I am out of line. :slight_smile:

Some days ago, as I was working on a Rails project, it occured to me that numerical values on ActiveRecord objects can be kind of annoying to work with and I got an idea for a solution that would give me an opportunity to dwell into metaprogramming and gem development - two fields on which I have no prior experience. The basic idea is to declare the units used in numeral attributes and exploit that knowledge for formatting and conversion purposes. Perhaps this has already been done before, although I wasn't able to find anything in a few quick Google searches.

Anyway, Instead of repeating myself, I'd like you to skim the README on this new project of mine:

GitHub - nielsbuus/united_attributes

I would really appreciate feedback on whether this is a good idea. And secondly, if you have the time, I'd would be nice to get some feedback on the details of the implementation as well. I know it has no specs yet, but that's because I'm using a Try-Driven Development process whenever venturing into new things. =)

This is really cool, thanks for doing this! I can see a problem ahead for currency -- I built a currency converter a while back that relied on a lookup of the current day's exchange rates. Not a pretty thing. You sort of tease at that with your £ vs # when discussing the duck, just letting you know that while your premise is extremely tight, and your execution as I see it here is really neatly done, that particular detail will make you cry when it comes time to make it real.