After doing some digging, the best solution for processing payment in my rails app seems to be using ActiveMerchant.  It seems fairly well documented, at least if you are using a mainstream credit card processor like Authorize.net.  For skipjack though, it’s a little lacking.  For example, it’s not clear what, if anything, you need to put in the ‘password’ field.  And no matter what I do, I can’t get any non-standard (by ActiveMerchant’s terms) fields to transmit, such as “comment”.  But perhaps the most frustrating thing of all, is when I had everything working and fine tuned in development, and I tried to throw the switch to production, by changing the login and using “:test => false” in the login hash.  After all, that is the only indication of where to send the transaction.  However, after several days of beating my head against the wall, I find this little gem (pardon the pun):

ActiveMerchant::Billing::Base.mode = :production

I almost slapped myself when I saw that.  Why in the world are there TWO places to set the mode?  Anyways, credit card processing now works, there is balance in the force, and everything is right in the world.