Start with whitelisting before you go through with canceling your service. Whitelist Wikipedia and whatever other resources you've got on your list. If this seems to work for you, then dump those resources and unplug your router from the cable / DSL modem for a month. Don't ask other people what resources you should have -- you know what you already use regularly and want to retain access to, or will after a month of whitelisting, and your coffee shop / office internet excursions will allow you to discover other resources which become important for home access in the future. Also, I doubt this life change will do you any good unless you cancel your cable / satellite TV service as well. Without the internet, the multitude of channels will allow you to browse and waste time the same way you did on the internet. Get Netflix or similar to mail you DVDs -- this will make you consider what you really want to see, and you can queue things up from the coffee shop.

If you just follow the instructions under:
http://plugindoc.mozdev.org/linux.html#Java
You won't have any trouble.
The command I ran was:

ln -s /usr/java/jre1.5.0_05/plugin/i386/ns7/libjavaplugi n_oji.so \ <br/>
/usr/lib/firefox-1.0.7/plugins/libjavaplugi n_oji.so

Just correct the version numbers and that should work.