Vlad sent around a very good article on good Java coding style, which we all liked. Most of the suggestions are exactly what we do here, with a heavy functional influence on our Java code. A sample:
Final is your new love: More and more Java developers in the teams I’ve worked with, started to use final. Making variables final prevents changing those values. Most often, if you reasign a value, it’s a bug or you should use a new variable. Final prevents bugs and makes code easier to read and understand. Make everything immutable.
Read Stephen Schmidt’s Next Generation Java Programming Style.