alternatives to spikes on wood floors?

Polycrystal makes a product called "cone-coasters." You can read about this on their website. I had the same problem you had. Cone-Coasters solved it.

http://www.audiopoints.com has brass coupling disks.

thanks to all so far. again, this is why i love this site. i'll consider your recommendations (the penny solution is definitely the most creative). As for whether "i should be using the spikes" i appreciate your take GS5556. I found that there was a noticiable difference when i put my old 3.6s up on spikes so i was just assuming the same would hold for the 6s. Unfortunately, i am limited in terms of speaker placement (they are close to a wall behind them and not far from walls on either side). Perhaps in this situation getting the speakers up on the spikes seemed to open up the sound (at least they did for the 3.6s) and provided a cleaner, less muddy bass).

anyway, thanks again for everyone's help.

Hey, maybe it's just me -- or, more likely, the exceptionally spongy nature of my floor "hardwood" floor -- but I've had my Thiel 2.3's on spikes, and the spikes on pennies, for about three years. So far, the spikes have literally drilled through about 8 pennies (I replace them from time to time). I'm seriously considering a major upgrade . . . to nickles. Figure it will cost me about 30 cents for a full set of six. I think it might be worth it.

Some people use big round furniture glides instead of spikes. They're cheap at Home Depot.