I had something similar happen to me once... I had gotten a 2nd interview towards the end of the summer which was more like an orientation in that the boss showed me where my desk was going to be, we agreed on the pay and benefits, and I was even asked if I'd be available to go to a conference later in the fall -- that they had to submit for plane tickets, hotel reservations etc very soon if I wanted to attend. Then 9/11 happened. Since this was a research lab, some of their grants actually came through the DoD, so a few days after the attack, I e-mailed the boss and he told me that they were not going to be able to hire any one until they knew the fate of their grants. It sucks, but sometimes the timing is just bad, and you just have to move on.
We are heading into the fall / winter, and many retail stores will be hiring for seasonal work for the Xmas shopping season. Jobs may start opening up in other areas. And just because you're hired for a seasonal contract, treat it like it is a permanent position; you never know if they may use this season to see who'd they like to hire on a permanent basis. In my current job, I was originally given a short, 2-month contract to help the company get over their end-of-the-quarter hump, but at the end, they took ~20 of us aside and extended our contracts indefinitely. And several years later, I am still working for them.
Good luck in your job hunt!