Dan Moore!

jad

If you've never used jad then you're missing out on a great tool. Jad lets you easily decompile java class files. It may be shady legally, depending on what contracts you've signed, but it's definitely useful in debugging and understanding behavior of java applications. It couldn't be simpler to use. Just run

jad classfile.class

from the command line, and you get a java file (named classfile.java) in the same directory. The names of the variables aren't fantastic (s1, s2...) but it sure beats reading the bytecode output of javap -c.

Note, it's free for noncommercial use, but if you want to use it commercially, contact the author for terms. And if you get a chance to download it from the above tripod.com link, grab it and store it someplace else, because the page often is unavailable due to its exceeding bandwidth limits.