Finishing your basement is a wonderful way to increase the square footage of your home, but it can be a very expensive project. Although there are some material alternatives to drywall (such as wall paneling and proprietary systems such as Owens Corning's) they can be costly. Fortunately, there are some effective techniques that can help you use that space sooner rather than later without the expense of drywall or its competitor products.
Finishing Foundation Walls
Clean concrete surfaces by applying tri-sodium phosphate (TSP) with a scrub brush.
Apply foundation sealer to surface with a paint brush or roller and allow 24 hours to dry.
Apply your paint. Use several thin coats as opposed to one thick coat. This will give you a much harder surface.
Optionally, you can also install window blinds as "wall-panels," which should be spaced evenly (every 1 or 2 feet) across one or more walls.
Finishing the Ceiling
Tack up one end of 4-foot wide fabric to the ceiling against one wall using your staple gun.
Unroll the fabric and tack it up to the ceiling at the opposite wall and cut the remnant. Allow the fabric to sag substantially. It doesn't matter if it touches the floor.
Start another row about 8 to 12 inches from the last and repeat steps 1 and 2.
Repeat step 3 until the entire ceiling is covered.
Attach wire or string with a wood screw to the ceiling along a wall perpendicular to the fabric and pull it tight to the opposite side of the room (below the hanging fabric).
Repeat step 5 by evenly spacing wire or string every few feet parallel to the last. This will give the ceiling covering a "draping-scallop" effect.