Standmount speakers - alternatives to spikes?

I use Vibrapods with terrific success. Decoupling is best in my view if you like to preserve all the energy of the music.

Why don't you just used floor protector disks or even pennies under the spikes?

I'm drawing a blank on the name but there is a spike that has floor protector built in. Not attached but it moves with the spike if you pick it up. They advertise in Sterophile...
Oh here, I think this is them
http://www.tnt-audio.com/accessories/superspikes_e.html

I hated having spikes on my speakes on a wood floor, major production to move them.

These work better than pennies. I sell these but tried the pennies myself a month of so ago, the spikes made a hole almost all the way through and would have gone through eventually.

http://www.starsoundtechnologies.com/apcd2.html

Your spikes probably use a standard thread such as 1/4x20. If so, I recommend standard threaded furniture feet which can be found at Lowes. Or, while at Lowes, you could get some hex bolts and affix rubber bumpers/pads to the bottoms.