I read constantly in the news about security holes in Java, so I thought that I should not allow any webpage execute Java programs, unless I allow. And currently there is a huge security problem, and update comes at next month. So, for now I simply have uninstalled Java, to prevent any chance of infections.
On top of that, I mostly use Java for one webpage only.
I use Firefox (14.0.1), if there is a plugin for that, it would be great. It would be even better if I could choose which Java filenames can be run (on that website).