alternatives to spikes on wood floors?

Rockvirgo, the men in the black helicopters are headed over to your house right about now....:)

Thanks Karls, I better put the kettle on. Did I mention how handy $100 bills are for lighting the stove?

You could try Vibrapods, that's what I use between my floorstanders and a piece of laminated glass on carpet over hardwood, suspended floor. Sounds very good to me.

http://www.soundstage.com/synergize/synergize011999.htm
http://www.vibrapod.com/Reviews/tas.htm

Harmonic Resolution Systems Nimbus pucks. Info at www.avisolation. They've worked wonders in my system.

I really wouldn't fret too much over this. Your speakers are probably heavy enough that the difference would be negligible. In fact the spikes could possibly make the sound worse, by exciting the floor boards.