Does anyone know how to make a model connect to a remote database and
only for that specific model?
That way I can do the typical CRUD functions on a remote server?
AFAIK distributed transactions with Ruby/Rails is an unsolved problem.
If neccessary, your best bet is probably talking to a Java or .net
-based backend over a web service, or perhaps having a look at JRuby;
which can probably work with JTA.
However, if you, like most rails/php/web/mysql programmers, don't care
about or need data integrity, connecting one of your models to a
different db is fairly simple.
Start at <http://wiki.rubyonrails.com/rails/pages/HowtoUseMultipleDatabases>,
and/or search this groups archives for "multiple databases".