How do you enhance a bad listening room's accoustics without breaking the bank? thoughts?

I am looking at a cork wall covering product to help enhance my listening room acoustics. The room is in a condo and shares duty as an "L" shaped living / dinning room. As I have neighbor's on either side I was thinking of doing the one wall where the speakers are placed and the opposite wall where I have my sitting position (The Coach!).  I was thinking the entire sitting room wall (10x8) and the speaker area (10x8) on the opposite wall. This may also have the additional bonus of helping to reduce the noise coming from my stereo into those condo's next to me?
I was wondering what people's experience has been and successful materials used as wall coverings or panels.
If handy, you could purchase Owen Corning Panels and cover them with your favorite fabric. This approach will save you lot of money.
Before you leap into solutions a quick review of Get Better Sound by Jim Smith is worth a try.  Plus, its very inexpensive to set up a 30min conference with Jim; he's very nice, patient and helpful.

He will ask for a diagram and pictures of your room.  He's equipment agnostic; he'll focus on placement and potential room treatments.

Best money I ever spent!
Pick up a dozen or two 5' artificial Ficus trees from a big box discount home dec store like At Home (@Home).  Scatter the artificial trees around the room focusing on behind and to the sides of the speakers and behind the listening position.  The artificial Ficus trees act as sound diffusers and absorbers.  

I bought mine at At Home for $40 each.  Completely converted my listening room, got rid of all kinds of room problems.  And they are appealing as room decorating accessories.