I'm running out of ideas, so maybe you all can help me?

I have two interns coming in from out of town for 3 months this summer. They will need short-term housing that is furnished. We investigated corporate housing, but all the options are extremely expensive. Even the crappy-ish places are $89 - $99 per night. Both interns will have a $750/mo stipend for housing plus they will be making a salary. Both are responsible graduate students and I assume neither will have a car (I know that one won't, I haven't confirmed with the other one yet).

We've tried craigslist, sublet.com and uloop.com with no luck. I've put something up on the bulletin board at work (such as it is) but I don't expect that to really pan out.

Any suggestions on places to find short-term housing?