I don't see a whole lot of creativity here. Almost all of these suggestions are for various parts of the US. The world is quite a bit larger than that you know.
A few from my list:
Cambodia.
Afghanistan, among the locals. Playing with the foreign troops is for tourists.
Northern Lapland.
But since you have severely limited time and funds, I would take WaltA's advise and go to Nova Scotia.
With a bit of luck, you might even be able to stretch the money all the way to Scotland. The highlands are amazing in autumn.
I vote Cambodia too, and I loved it there, but it's a ridiculously long trip from Indiana to Phnom Penh, and he's only got a week. As for Afghanistan, it's a huge pain in the ass for an American to get over there without a solid reason, and add to that the fact that there are only three places in the States where one can even get a visa (NY, DC, LA), all of which are quite far from Indiana. And of course there are serious kidnapping threats that are severely heightened for people who've come in on an American passport, etc etc. It's a beautiful country but I don't think all the "sense of adventure" in the world would make it truly worth going unless you had a real plan and a good reason to be there. If you're not going to shoot anything war-related, then Uzbekistan, Turkmenistan, and Tajikistan would all be similar, safer places to visit. None of them, though, are good choices for a week-long trip!
To OP - if you're not digging going abroad, then you could also try the Northeast. Fly to Boston, rent a car, and road trip all the way up the coast of Maine until you hit Quoddy Head, which is a stunner of a place. Lots of nifty Americana in between, too...various historic/quaint New England towns (Lexington/Concord, Rockport, Portsmouth NH to name a few) and heavy-nostalgia coastal spots like Hampton Beach, NH. And the drive from Boston to Campobello Island (just over the Canadian border) is only 6 hours or so if you do it straight, so a week is more than enough time and would probably allow you to drive all the way to Nova Scotia as well (another 6 hours). Check it out!
Oh, and following what others have said...the end of this month is perfect timing for fall colors in New England (Maine especially).




