Our only concern is that we might be forever taking the cover top on and off again as we need access to the burners themselves. And depending on the cover we get, it could be awkward to find a place to store it out of the way while we use the burners. Then again, we're usually only using one or two burners at a time, so maybe finding something that only covers half of the stove would be a good option.
We discovered that stove top covers are actually already commonly used in RV and yacht kitchens where counter space is truly at a premium. Most of the products we found on the internet are intended for these spaces. Here are a few:
For full-sized stove tops, we found a few sites that will make custom covers:
Of course, if you aren't so picky about an exact fit or how it looks, we think you could forgo many of these options in favor of few wooden cutting boards balanced over the burners. We could also have a plank of raw wood cut down to size at somewhere like Home Depot or Lowes.
Do you cover your stove top? Do you find it useful for creating space?