http://stackoverflow.com/questions/16828/how-do-you-do-a-case-insensitive-search-using-a-pattern-modifier-using-less
Enable case insensitive searching in less by type -i or launching less with the -i flag. Genius.
http://ajaxwhois.com/
Excellent domain search tool, ajaxified, and supports multiple (even configurable) extensions, probably not 100% reliable though if it relies on whois.
http://www.hipmunk.com/
Search flights and see them laid out in a grid that shows take off time, layover time, stops, and sorts according to "agony" which tries to factor price, layovers, etc.
http://domai.nr/
Search across all the funky domains, short domains, etc. Awesome, instant, domain search. :-)
http://www.searchtempest.com/
Search all the craigslist sites from one interface. It loads local results in iframes.
http://addictomatic.com/
In one place search yahoo, Google, Technorati, WordPress.com, YouTube and lots of others. Punch in a term, see the top results from a whole bunch of useful sites. Great idea. Hat tip Seth Godin.
https://ssl.scroogle.org/
Scroogle via SSL at ssl.scroogle.org.
http://ripple.org/
Support charities by using ripple to search, to view ads, etc. They donate 100% of their revenue to charities, so it's not a business per se.
http://www.sitemaps.org/
Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling.
http://www.goodsearch.com/
Your chosen charity is paid if you search the web with GoodSearch, it's powered by Yahoo.