Google

 There were a couple of new and useful things I learned about Google last class.  I had no idea there existed a thing as the Deep Web, which Google cannot access.  I also did not know about the Page-rank algorithm and how sites use Page-rank Optimization to try to exploit it, or that Google has a death penalty.  The most interesting stuff, however, was on the practical side.  For instance, now I know that I can use "-" or "+" to force Google to exclude or include phrases.  This will be helpful in future searches.  Another useful tool is the Advanced Search, where you can restrict searches by domain among other things.  Also, I thought it was very interesting that Google caches sites, so that if the site is down for some reason you can still access a version of it; or that you could use it check information from a much older version of the site.  I just wonder how long it will be before people start having it surgically implanted.