Search Tips, for Google Searches:

• Add "site:xyz.com" as part of search to narrow to a specific site
  
• For example: site:hp.com
• Add "-site:xyz.com" as part of search to eliminate a specific site
• For example: site:hp.com -site:forums1.itrc.hp.com -site:forums2.itrc.hp.com
  
• Also, use "intitle:xyz", "inurl:xyz", "intext:xyz", and "text:xyz"

Searches

• altavista, Ask, Dogpile, Google, Google Suggest, IceRocket, Mamma, MyWay, Verity, ViewPoint, Wikia Search, Yahoo!, Long List of search engines
• Advanced Internet Search: altavista, Ask, Dogpile,  Google, IceRocket, MyWay, ViewPoint, Yahoo!

Search Plugins (for Mozilla browsers):

• Firefox earch Engines
  
• Flock Search plugins
  
• Mycroft project provides a collection of Sherlock & OpenSearch Search Engine Plugins
• For example: gmail
• Creating_MozSearch_plugins
• Creating_OpenSearch_plugins_for_Firefox
  
• Quick start guide to creating Mozilla-Search plugins