Reusing a Model Built in R

When building a model in R, how do you save the model specifications such that you can reuse it on new data? Let's say I build a logistic regression on historical data but won't have new observations until next month. What's the best approach?

Things that I have considered:

• Saving the model object and loading in a new session
• I know that some models can be exported with PMML, but haven't really seen anything about importing PMML

Simply, I am trying to get a sense of what you do when you need to use your model in a new session.