Yo!

So I am in the Republic of Georgia as a volunteer teacher, as I have mentioned before. Steam here is MUCH cheaper than in the US, about half price.

I took Steam online for the first time today since arriving here and noticed it offers me Georgian prices, despite me and my account being American. Max Payne 3 is $29.99, Alan Wake is $12.99, etc. etc.

Anyone know what happens if I buy those games here, then try to install them in the US?

Nothing. They will work without problem. I have used my account in couple countries and never had any errors or something like that.

I think nothing out of the ordinary happens. You still paid for them, so they're yours. You're not getting charged extra or anything.

Probably nothing, but make sure they are in English.

EDIT: I see region locks are now more explicit – this is the Russian storefront for Max Payne 3. I have no idea what region Steam assigns Georgia to, though. Here in EU2 it's €49.99.

The prices (and game version) that is available for you to buy depends on your IP Address, not where you account was created at. Depending on the title you want to purchase, it is possible that you may be shown a different version than the one available in the US, but whether that version will work there depends on the title (I think).
I think (but I'm not sure) that Max Payne and Alan Wake are international releases (though a low violence one may exist for Max Payne) and should work normally, but best to ask.
Also, if the game's ID is the same both for Georgia and US, then it is the same game, and you should be able to play it just fine.

And make sure the game is not locked for US. I think that if you buy a game witch is locked for a region in another region, it will be locked when you move back to the region where is locked. Though I do not think this is much an issue with US.

(that did not make any sense at all....)

You MAY have an issue the first time you try to purchase a game there. If it happens, send a ticket to support stating that you are living / residing in Georgia and they can "unlock" your account - allowing you to purchase from the store.

(I love this... allows me to get around the over-inflated Australian prices by purchasing through the US store - haven't been game to try the UK / Russia (LOL) ones yet :P)

I thought of that. They might also refuse my card, like GOG does.

I think a lot of people would be glad to help you out in exchange for GOG.com games, especially if you can get your hands on any gift codes for these :P
But of course, such codes no longer exist...

If you want to be on the safe side, and given how "sensitive" Steam seems to be with region lock, it would be better to ask Steam's support. If you don't want the bad surprise of having some games magically removed when you move back to US or your account locked.

If the games you bought are region locked, you'll not be able to play them outside from the region you bought them from, if they aren't everything is good.

First off, unless you have a local payment method, you most likely won't be able to make any purchases. If you do manage to make a purchase be aware that:

Some games may be regionally locked so that they can only be played from your current region. Problem is, in 99% of such cases, there will be zero warning. I have only seen two games offer such a warning on the Steam store page - Max Payne 3 and Dead Rising Off the Record.

So always check out the Steam forum for that game to see if anyone there knows of a block on the title in question.

Don't waste your time asking Steam support about region locks. They will LIE to you and tell you that they don't regionally restrict games purchased directly on Steam. The exact wording they will use is "Purchases made directly through Steam are not restricted by territory."

This.

But you need a georgian payment option for it to work. Back when I was there, I had to use a german IP to make purchases (which was, ironically, against their ToS...)
I've encountered a few "activation issues" with my german IP, but never playing the games. Even games that are downright illegal in Germany (Hello, Dead Rising 2).

I think that the playing restriciton is unique to Japan (or SE Asia) and its PC gamer discrimination.

You must contact Steam support to make purchases from abroad. This is to prevent fraud.