People searches: Zabasearch; Spock; Spokeo
Newspipe: "Newspipe is an RSS/Atom aggregator with a difference: It allows you to keep track of your feeds through e-mail"
Wikipedia Reputation and the Wemedia Project
In this Wikipedia healing experiment Prof. Halavais introduces errors into the Wikipedia and discovers that they are corrected within hours.
Well Put: The problem with the Wikipedia concept.
Digital Maoism: The Hazards of the New Online Collectivism: I agree with everything in this essay by Jaron Lanier. Wikipedia is his big example. There is a follow-on interview on the Philosopher's Zone program from ABC radio (Australian national radio) that's pretty engaging.
Amazon Book Search: You can search not only for book titles and keywords, but for actual contents.
Web search with result clustering
Subject Index to Literature on Electronic Sources of Information
Free Online 1911 Encyclopedia: "The LoveToKnow Free Online Encyclopedia is based on what many consider to be the best encyclopedia ever written"
“Google SMS (Short Message Service) enables you to easily get precise answers to specialized queries from your mobile phone or device. Send your query as a text message and get phone book listings, dictionary definitions, product prices and more. Just text.”
I've used this a handful of times and it is a great service. The message comes back in a few seconds—it can be faster than looking up an address in a phonebook. This is especially nice if you have a bluetooth phone and PDA: you can copy the returned results and paste them in your address list. Once you have typed "10002 pizza" into your Palm and gotten back a list of slice vendors on the Lower East Side you will be hooked.
“Google Scholar enables you to search specifically for scholarly literature, including peer-reviewed papers, theses, books, preprints, abstracts and technical reports”
While this is far from compendious enough yet to displace the Science Citation Index (for example), it is very interesting and is likely to become important, as Google's good sense and beefy resources are behind it. And it is definitely a boon to scholars who don't happen to have institutional access to literature databases.
Dowser: "Dowser is a research tool for the web. It clusters results from major search engines, associates words that appear in previous searches, and keeps a local cache of all the results you click on in a searchable database."
Public Radio Downloads: The 43Folders website maintains a list of places where you can go to download public radio programs.
Google Maps API: 'The Google Maps API lets developers embed Google Maps in their own web pages with JavaScript. You can add overlays to the map (including markers and polylines) and display shadowed "info windows" just like Google Maps.'
Apostrophes and Google Don't Mix: When phrase searching in Google (and most likely plenty of other places) it might be better if the phrase does not include an apostrophe. If a typographical or "smart" apostrophe is used in the original then it might be missed in the index.
55 Ways to Have Fun With Google: A free PDF of the book by Philipp Lenssen is now available.
Latent Semantic Indexing: Increasingly used by Google. (This means that they are depending more on semantic analysis to determine ranking of results, rather than simple keywords and link analysis.) You can even do a "semantic" search on a term by prepending it with "~". For example, searches on "~word" and "word" return different results.