Selection Search - With this extension you can easily search for text you have selected.
start.me - A Modern-day bookmark manager. A place for your favorites. A news feed (RSS) reader. A browser startpage. A portal for your team.
Trufflepiggy - Quick Search - The all-in-one search addon: just select and search. Find on multiple websites at once. Search via overlay, context menu or omnibar. Featuring anonymous profiles. Easy setup: select from 1000+ user generated searches. Cross-browser sync.
Protopage - The best iGoogle alternative. Chris Pirillo calls Protopage "The best designed".
Swift Selection Search - Swiftly access your search engines in a popup panel when you select text in a webpage.
Netvibes - First personalized dashboard publishing platform for the Web. Digital life managment, Widget distribution services and brand observation rooms.