This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
There are quite a few good profiling tools available commercially. I suggest taking a look at the Optimizeit and JProbe. If you are looking for a free tool than take a look at Jack Shirazi's list. In general, I don't think I have come across a free profiling tool that does even half of what most commercial tools do. If you have identified a need for a profiler then I suggest invest in a tool like Optimizeit or JProbe.