What are the various methods you all have used for reducing sound on your track? What have you tried that didn't reduce sound, and what did reduce sound, and to what extent?

Things under the track:
From what I have gleaned from forums so far, Homosote seems to be the best product for permanent track layouts. It is, after all, used for sound deadening. I am looking for alternatives to Homosote, as my track (probably a 4'x8' layout) will be something that I envision changing every couple months. If I used Homosote, I think I would need to either cover it with something else (to hide all the extra holes from previous track layouts), or fill-in all the old holes.

Does carpet or felt actually reduce sound to any extent?

Track Mods:
I've read about removing certain tabs where the tracks meet, and it appears this is worth the effort.

Sanding and/or filling-in at joints may also reduce the clacking, but it appears this would have to be done with each new layout.

Has anyone tried filling in the underside of each piece of track, specifically each cavity to side of the joint, with some foam or rubber tape or something?

Your opinions and experiences are appreciated.

I'm going to give flooring underlayment a shot.

Where do you guys find the cheaper rolls of stuff to lay on the tables? I went to walmart and they didnt have anything that would work and home depot just quoted me prices for carpetting that looks like grass, it was $41 for a 12'x4' section that would fit my table. Im on a budget, like most people are, and any unecessary costs are getting cut from the funding. At this point Im about to just endure the clackity clack and paint the table green.

I used green felt....it was on sale for 3 bucks a yard...I needed 3 yards...so I had 9 bucks in felt...

When I do my next table, I will probably just paint it, and skip any carpet or sound-deadening material. My initial opinion is that the underlayment I installed isn't reducing any noise (unless I lay under the table :) ). Removing the tabs on the pieces and presing down the power rails at the splits is all I think I will do next time to reduce clickety-clack.

The last track I built I laid it down and traced out the layout. I then marked each peice of track as to spot it goes.I use a silicone then at the spots where the track hits the table. Lay the track into the silicone and nail or screw it down.The silicone acks like a cushion for the track. As for the rails. Super glue each spot under the track where the rail is showing.Also for more strength run a bead of glue around the rail on the surface.Be careful not to use to much. As for the tabs. Grind off the lock peice on the tab. This will let the track lay out flat instead of the little hump you get when the track don't lock.
When the track is down place a peice of fine sand paper on a sanding block and sand the topws of the rails to removbe and glue that dried on the rail..
Make sure you clean the tabs for the rail conection to be sure it make the right contact..
Hope this helps..
GB