This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
If what you want to do is to obtain a textual representation of the value, with two decimal places, DecimalFormat is indeed the way to go.
If what you want to do is to perform calculations using only two decimal places, then you should not be using floating-point arithmetic. Instead, you should do integer calculations, using "hundredths" (if you're doing currency, call them "cents", "pence" etc.).
Betty Rubble? Well, I would go with Betty... but I'd be thinking of Wilma.