if you are just looking to partition the space, what about hanging cloth panels? I did that in a friend's house to screen her laundry area from the playroom. We got 10 foot long 3/4" metal electrical conduit and hung it from the ceiling joists with conduit straps at each end. Get the straps called "broom clips" or "mineralacs" which have a spacer and a bolt and nut across the spring metal part -- makes it easy to take down and put up the conduit. We got nice print queen-sized flat sheets on sale and used drape hangers that are like shower curtain hooks with metal clips that snap onto the fabric (so no sewing involved) . You can also just clip the stitching out of the ends of the top hem of the sheets and slide the conduit through before you hang it.
Or, you could hang bamboo or matchstick porch blinds from the joists. These are usually available up to 8' long and 8' wide. Those vertical blinds people used to hang in front of patio doors aren't fashionable any more so if you put an ad on craigs list or something you might be able to get those free or cheap and they would work, too.
Another option that builds a quick wall if your ceiling is 8' or less tall(we've used this for theater sets) is to get narrow metal track and studs and sheets of insulating foam at a builders supply store. Get the 1 1/2" furring type studs and 1 1/2" thick sheets of 4' x 8' styrofoam. Cut 2 sections of the track to the length of your wall, stick one to the floor with construction adhesive and the other overhead along the joists with tapping screws (be sure to use a plumb bob to line up the overhead and floor tracks). Stand the foam in the floor track -- if it is too tall, measure and cut it down with a serrated large bread knife. Then cut lengths of the metal studs to fit the vertical sides of the foam panel and slide them on. Screw the studs (using a battery drill and 3/8" self-tapping tek screws) to the lower and upper track and do the next panel. One advantage of this wall is you can use it for a giant bulletin board You can stretch fabric over it with a staple gun if you want it to look less industrial. Don't lean against it, though, because you can break through the foam pretty easily. If you decide you want a more permanent wall later you can pull out the foam, add more studs on 16" centers and hang drywall or paneling on the steel framed wall with tek screws.
many oddball home remodelling projects