SPoE: Sketching in Eclipse

After my last round of mock-up tools fizzled out, I moved on to other things. Today I had a coworker inform me that Eclipse has a mock-up plugin. After giving it a spin, I have to say it’s the best of all the apps I’ve tried to use. I am amused that the solution to my problem has been sitting right under my nose this entire time. Sadly, it’s a non-free plugin, but I’m not sure what that means yet. If I can get a feel down for basic usage however, I’ll be happy.