jLogMan displays the current state of java.util.logging's Loggers and
Handlers in an "Outline" (a tree table widget). With it you can create new Loggers and
Handlers and change logging levels. There are Actions to save/restore logging
configurations to/from files and an option
to apply the configuration at startup.
It can be dropped into any swing app (tested with jre 1.6 and 1.7); there is a NetBeans
plugin. See the wiki for details and docs.