USPS web services and Ruby/Rails

Hello list,

I was wondering who here already had to work with USPS from within a
Rails
app to implement fullfilment. I was working with Fedex, implementing not
only cost calculation but also the shipping request, void, cancel
shipping
etc. However, I have no experience with USPS and I don’t know how
complete
their SOA architecture is. If you have worked with it to some level,
would
you mind sharing your experiences?

Thanks,

Marcelo.