Social Bookmarking is a system that lets people collaboratively classify and link to web pages. Typically, these tools allow people to bookmark web pages to a server and tag them with keywords of their choosing. By moving these bookmarks to a server, they can be accessed anywhere that has internet access. More importantly, they can be viewed by anyone and, when combined with other people's bookmarks and tags, provide a new way to browse the web.
To make bookmarking easier, these applications have a bookmarklet tool which allows you to press a button on your browser.
Aggregators are programs that pull in news (RSS) feeds. They can be downloaded as a stand alone program or you can use an web-based aggregator such as:
helps you publish your RSS feeds.
Based on the concept of six degrees of separation, these sites are set up to help you advance your career by finding people you have an indirect link through your contacts.
Sure you know Google, but you may not know all of the services they provide. Aside from the ones listed elsewhere on this page, some favorites are: