Oh can you get me some big red chewing gum and some cinnamon crest toothepaste :D

When are you going. Weather can be hot and muggy in the summer up to the end of Sept. Gets pleasant after that. You can rent a bike there and go up in the mountains of Virginia and West Virginia. Pretty country.
Safety is an issue, but then again most major cities are. Brother got mugged in Amsterdam, I got hassled in Paris, friend got robbed in Hamburg, I almost had a run-in with a druggie in Zurich, my CC numbers were absconded with in London and major purchases made, had a friend robbed on a train to Milano, another friend hit by gypsies in Rome, etc., etc., but I have never had any problems in DC. Lucky I guess, but always watch your back and keep your city sense on high. Lot of good places to go, try to get in Jeffersons old place at Monticello as well, maybe some of the civil war battlefields, of course the Air and Space museum. If you can, try to rent a bicycle as well and ride all over the place, especially along the river or the canal. Try to get in a baseball game, even if you don't understand it as the team is new and they are trying real hard to build up a fan base. A tour of the Capitol BUilding is worth while as well.
Don't expect much in great cuisine, but you might find some good things in Georgetown.
Enjoy!

I didn't realise Tyne and Wear was that popular

Actually yes they are...I do have to write a paper though about what I have learnt, how it will change my practice and how I can cascade and dissemminate strategies throughout Nottinghamshire Local Education authority.
It's through the Teachers' International Professional Development (TIPD) Programme.
I do have to pay for any transfer's, meals, entertainment, car hire etc
They pay the cost's of travel and accomodation. ANY teacher can apply to go on this...They are not guaranteed which country they will visit or how long the trip will be. It depends on how much your LEA value the professional development of staff and you submit as a group of professionals not individually. We are a group of 10. I am going in the October half term... so in effect I will be working during the half term break. I get the evenings free from 7pm and need to be up and ready for the school working day to be in schoolf for 8am.
However depending on the country (A colleague went to Nigeria) Your host MAY take up your evening in an attempt to show you customs of the country etc

October is great! Go out and see the countryside on the weekend if possible. We hosted some folks from Japan on a similar program when I was a grade school teacher and that was fun. Lot's to talk about.
Mentioned a bike rental, but a car may be more convenient and cheaper.

Your going to school? Make sure you're tooled up. And wearing body armour.

Naw, just pack a .357 mag and take the teachers entrance past the metal detectors...

Not greatly helpful, but a writer called George P.Pelecanos sets his books in Washington DC from fifties to present day. I recommended them to a friend going there and she said they were pretty good for local colour, atmosphere etc. BTW pretty good books IMHO