I've been demo'ing the Swing builder by instantiations.
http://www.instantiations.com/swing-...er/default.htm
It is hands down the best GUI editor for Java I've ever seen. (I've tried most of the freeware/shareware ones out there.) It's free for 14-days, then after that you can buy it or continue to use it for free, however with a loss of several features and functionality. There is a list of the features it hacks off after 14 days, and it's a pretty hefty list of missing stuff.
I'm seriously considering dropping the $99 for a personal license. It's a really awesome tool IMO. (After months of trying to teach myself raw GUI code.)