When I look at all the cool technology that is available to classroom teachers, it is easy to be seduced by a lot of flashy, "Gee Whiz" applications. You look at them and say, "Wow - wouldn't it be cool to...", then somehow, you never get around to actually using them.
On the other hand, what about the not-so-sexy, practical tools that I actually put to use? The ones of real value? The Mary-Anns of my little island, if you will? (Sorry - a totally wasted youth coming back to haunt me...)
The type of application that springs to mind is Mapping Games.
I've been using these in my classroom for the past several years to help drill students in study sessions for geography quizzes. They are practical, immediate and visual ways of studying that target a different type of learner than traditional pen and paper petagogy. If I have a student who swears he or she can't memorize a particular map, half an hour of traditional drilling - ("Okay, what's this one? Uh, huh... and this one? And what was the first one, again?"), followed up by half an hour or so of playing a mapping game will almost always nail the fundamentals into his or her brain.
Okay, granted - this isn't higher-level learnng we're talking about here. This is not going to inform a student in any meaningful way about the history of a conflict or the richness of a culture; this is rote memorization. There is a place for that, though, and mapping games really help with the tedious gruntwork.
Anyway - useful online mapping games:
http://www.lizardpoint.com/fun/geoquiz/ - These are games that I've been using for several years. They are very basic, but really get the job done. There are mapping games here that cover dozens of different topics, from very basic to very esoteric.
http://www.mapmsg.com/games/statetris/ - If you are familiar with the old videogame Tetris, these games will make instant sense to you. If you don't know what I'm talking about, they will confuse and dismay you. These games are seriously addictive. Please, for the sake of your own sanity, if you play these yourself, start on the Easy level. (By the way, the fact that this set of games sucks you in so thoroughly is a very good thing when you can get a student into that zombie-like trance, where, quite against his will, he learns something.)
http://www.sheppardsoftware.com/web_games.htm - I've just discovered this series of games. They have several different sets that focus on the United States, Europe, the Middle East, Asia, South America, etc.. Each set starts out with a very basic, easy(ish) game to lull you into a false sense of complacency, then presents you with more and more challenging games on the same theme. By the time you've worked your way up to Level Three or Four, you REALLY know this stuff!
I see all these as being particularly useful for 5th grade and up. I looked for a New Hampshire mapping game to help out the 4th grade with their New Hampshire unit. I didn't find a GAME, exactly, but I did find this page of very cool classroom support materials. I hope it's useful.
Hmmmm.... maybe we should have student's design their own online New Hampshire mapping game. A very Ginger-y idea.