Asynchronous code reviews work well, though make sure that the software sends nasty-grams after no feedback for a few days.
JConsole is a decent tool. I'm surprised I've never used it before.
We have a nice JMX idiom where you register a class and tag methods with a @Managed annotation. This avoids the need to create separate interfaces and implemenations for MBean classes.
Google Guice is nice for the static type checking and annotations. I've always hated XML files for configuration.
Try out jDBI from Ning's Brian McCallister when you want to directly hook into your db.
TestNG is sweet. Classifying tests to group them as fast, slow, etc., is really nice.