INTERNET: I've been using Ted Mielczarek's FlashBlock program for some time and highly recommend it for getting rid of unsightly flash ads. Checking his Mozilla page today I found a few other gems that are also useful.
* Nuke Anything: This plug-in ads an option to your right-click menu to get rid of anything on a rendered webpage. You can select big chunks of text, images, tables, whatever, select 'remove,' and it's gone in a fraction of a second. To get everything back to normal just hit refresh.
* Plain Text Links: This little badboy lets you treat a url without an A tag as a hyperlink. Very hand when reading message boards and the like.