they make wall panels for media rooms that flatten out the sound. you can get plain solid colors or decorative patterns. the more cloth you spread around(furniture/rugs/etc) the more you will deaden sound as well.

Agree with the last note. Add material all over. Small scatter rugs do very little. Use large area rugs, but they needn't be super thick pile. Consider also curtains -- i think you can find styles for people who don't like curtains, maybe special window treatments made of cloth that are energy efficient -- they also deaden sound. If you have large bare walls, consider hanging a tapestry, fancy rug, or fancy quilt. That will go a long wall toward solving your problem.

I am really surprised to hear you have that problem with wood. When I first moved into my house I had same problem. I have wall to wall travertine and Oh my gosh I couldn't stand it. Oh I feel your pain. I added a book case floor to ceiling and about 12 feet wide that helped a lot and I hung a decorative rug (wool hand carved) on the wall. That helped a lot I also added 2 other floor rugs but they are thick wool contemporary hand carved type rugs. I don't have the problem anymore. Find something you like in a rug and hang on wall like art. Here is a trick I use to hang them, get carpet tack strips from hardware store cut down to length of what your hanging and nail them up on wall (angle the nail down for strenght) then just get a helper and lift rug and hang the top 1.5" or so on the carpet tacks. Works like a charm.

Have you ever been to a Cracker Barrel restaurant? OMG noise bouncing off the walls, floors like crazy, food is great, but have a headache upon leaving, use bigger heavier rugs, and fabric furniture where ever you can, even heavy drapes will help, you need something to absorb the sound take up the echo...

I agree that sound deadening materials are the answer. BTW, if you don't like the idea of hanging a rug on a wall, maybe hanging a nice quilt would fit in better with your decor.

If echoes are a big problem, that suggests you have certain surfaces off which the sound is bouncing. I would try to experiment to figure out which walls are contributing the most to that effect. First, get everyone to be quiet -- for just a few minutes. Then, make one loud sound while people are in different places in the room. The sound can be just the clapping of hands, one person clapping just once or a few times, or maybe two glasses touching as in a toast. Listen closely. If you're lucky, you might be able to identify the primary surface or surfaces that contribute to the echo problem. Then you can concentrate on putting sound deadening material on those surfaces. That might save you the trouble and expense of putting up sound deadening material all over the place.