You could always please the wife and the linguist in you by starting (adding to?) a collection of translations of the Bible and then read through a few of them and comment on translation errors. That might be interesting.

I'm thinking about teaching myself Koine sometime in the next few years. Already have an edition of the NT, plus two commentaries on how to approach learning Koine based off of the NT alone. While I don't care too much for Evangelical shadings of meaning, I figure it shouldn't take too long to learn the basics of the dialect.