Both Firefox and IE7 have "search bars" that allow you to look up things easily on Google, Wikipedia, etc.  Searchplugins.net makes it simple to create search plugins for other sites as well.  So I used it to make a bunch of baseball-related search plugins.

All you need to do is switch the search engine in your search bar (in the upper right hand corner of your browser), and you can look up a player just by typing his name into that bar.  If you have Firefox and an extension like Context Search, you can also look things up by highlighting them on web pages, right-clicking, and choosing the appropriate search engine.

My plugins can be found here.  They include:

Baseball Cube

ESPN Baseball Player Stats

FirstInning.com

Minor League Ball - Comments

Minor League Ball - Diaries

Minor League Ball - Stories

Minor League Splits

Rototimes Baseball

Rotowire

Rotoworld

Hit the "I" next to them to install them. All of the plugins work in Firefox.  Most of them should work in IE, except for the ones marked with the Firefox symbol.  The ones marked "last name" only accept players' last names; the other ones can handle full names.

There are also plugins on searchplugins.net for Baseball-Reference.com, Fangraphs.com and MinorLeagueBaseball.com.  Mycroft.mozdev.org has still others, such as Baseball Prospectus and Hardball Times.

I hope you enjoy these plugins!  I know that they save me a lot of time.