hardwood floors, area rugs, and spiked feet

We're putting in solid oak hardwood floors and have purchased decent quality oriental area rugs, one of which is going into my listening space to cover the flooring between the listening location and the speakers. The rug will extend under the speakers. So the question is, what to do to stabilize the speakers on top of the rug without the spikes damaging the flooring underneath. The carpet is pretty thick and dense; it won't do just to remove the spikes and depend on the speaker feet.

I need a method to somewhat blunt the spikes but still enable them to get down into the backing of the rug. It won't do to just round over the spikes; the weight of the speakers will still damage the flooring. I'm thinking there's got to be some sort of a combination of a disc and shallow spike setup. I looked in several catalogs but came up empty.

Surely one of you folks has run into this problem in the past?
how about putting a piece of Luann (ie 1/4 " plywood) under the speakers between the carpet and the hardwood? I have speakers directly on hardwood and put a chunk of 1" hard rock butcher block under them. This has worked fine. (Surprisingly my wife hasn't yet told me to get it out of there and it's been several months.)
Now that's a good idea. Two or three extra inches in each dimension (of the speaker's base) should give me enough room for fine tuning the position. Basic luaun (I think that's the spelling) carpet underlay is only about 3/16", and it's soft. That'd work.

Thanks for that!

I still think there ought to be something designed for this application that can sit under the spikes on top of the rug.
How 'bout a piece of sheet metal lined with cork? Wont make your rug look funny.
If your situation changes so that the speakers will not be on the rug, try spikes or cones (e.g., Audiopoint, Mapleshade, etc.) with coupling disks by Audiopoint (or similar) sitting on Herbies Big Fat Dots between the disks and your hardwood floor. Protects the floor, decouples the speaker and sounded better than spikes in my former set-up over an oak hardwood supported floor.
Don't use spikes, use a decoupling type device like the Aurios. It's been my experience that unless you move your speakers around alot, spikes don't noticeably damage hardwood floors. The marks they leave are quite small.
If the rugs are wool watch out for static electricity, I damaged some componets that way even though they were grounded.
Herbies Audio Labs' cone/spike decoupling gliders are designed specifically for this application. I used them on my carpet and will as well on my own recently installed hardwood floors' once the poly finish cures in a few days.
In addition to protecting your floors they also reduce floor-bourne vibrations and bring improved clarity to your speakers. They come with a 90-day money back guarantee so it's a no-brainer.
I agree with Jgiacalo, I use Herbie's Audio Labs cone/spike decoupling gliders under my rack spikes and speaker spikes. They are on top of thick carpet over hard wood floors. Floor protection and increased resolution was gained. These are a pretty cheap option and 90 days money back guarantee is a no brainer.
I really like the sheet metal and cork idea a lot...I like cheap fixes. Thanks SR!

And I just went to the Herbie Labs site and those decoupling gliders look like they are perfect... positioning will be a breeze with those. I'll get four for my rack for starters and try them out under a speaker to see about stability before I jump in all the way. Either way, you can't beat the price. I really like the Herbie TT mat I've got too. That was another nice cheap tweak for my Rega. So thanks to Jgiacalo and Joeyboynj on the Herbie suggestions.

But really, thanks to everyone who took the time to respond. I knew I'd find the answers here.
I used to use Nylon bolts instead of spikes when I had my speakers on the hardwood floor. No marks, easy levelling, and they slide without scratching if you need to reposition them.
Put a a coin under each of the sharp points of the spikes.
Another alternative is Grand Prix Audio Apex footers - have them under my speakers and love them sonically (and they can beasily adjusted for leveling, which is critical).
First, I must say that the "upgrade" to hardwood floors from carpeting in the listening room is a great move and something I wish I had done sooner. The improvement in the overall sound plus better bass response was fantastic. I think the addition of the wood flooring makes the floor much stiffer and this helps the entire room out tremendously. I machined my own brass discs to put under the spikes on my speakers. My speakers came with spikes. Spikes firm up the imaging, for sure. I listened to a pair of Sonus Faber speakers many years ago at a HiFi Buys in Atlanta. They were sitting on 4 inch thick stone slabs. The stones were an option. I think they helped the speakers out a lot. So consider maybe getting some thick stone slabs to put under your speakers. Still include spikes on your speakers to sink to the stone slabs.