OK, besides packing your own loaf of bread, bag of apples and jar of peanut butter....here are a couple of hints. Some of them work better when you are going abroad, others for domestic.
Check out
www.ratestogo.com for last minute (21 days in advance) bookings. You get a rebate back as well. If you want to book more in advance, you click on their partner site and pay a higher rate. This site is really good for Germany--so so for New York, Chicago, London, etc.
I also check out
www.hostelworld.com (or
www.bootsnall.com) to book private rooms in hostels. This also works a little better abroad, but I just used it last week to book the Y in NYC....What a surprising bargain, and not as bad as you would think.
For airfares going to Europe, just get something cheap to the continent, and then use a cheap European airline (ryan air, Bmi baby, hapag-lloyd express, etc.) to get you where you need to go. Hapag-Lloyd has a great fly-rail deal where you can go anywhere in Germany for something like 14 Euros (or maybe it's 14 Pounds). Some of these airlines run fares where you pay a penny in addition to the tax. Also, you should check out the international airlines sites in addition to orbitz, travelocity, expedia, etc. Keep Southwest airlines site bookmarked and buy your conference travel when it goes on sale....it almost always will go on sale.
The H-list has a monthly housing bulletin if you need a place (especially in Europe, but also the USA) or if you are leaving and want to sublet...
I get preliminary info on biddingfortravel, but I don't post there. The Admin is a stickler for following her procedures.
I also check out the cheap hotel-motels near the conference center. There is almost always something like an Econo Lodge or Super 8 nearby.
Another option that lots of people overlook is dormitory or campus housing. This is great in the summer--not sure that I would try it in the winter. I'm staying at a dorm in Salzburg with a swimming pool, and there was a health club at the medical student dorm in Toronto.
Best way to cut conference costs. besides writing grants? Cultivate friends all over the place and just stay with them!
(Many appologies for any typos...I'm on a German keyboard and it is giving me fits.)