TiddlySnip is a Firefox extension that lets you use your TiddlyWiki as a scrapbook! Simply select text, right click and choose 'TiddlySnip selection'. Next time you open your TiddlyWiki file, your snippets will be there, already tagged and organised.
Stumbleupon is a brilliant downloadable toolbar that beds into your browser and gives you the chance to surf through thousands of excellent pages that have been stumbled upon by other web-users