  The present generation of ground-based Very High Energy (VHE) gamma-ray
observatories consist of arrays of up to four large (> 12m diameter) light
collectors quite similar to those used by R. Hanbury Brown to measure stellar
diameters by Intensity Interferometry in the late 60's. VHE gamma-ray
observatories to be constructed over the coming decade will involve several
tens of telescopes of similar or greater sizes. Used as intensity
interferometers, they will provide hundreds of independent baselines. Now is
the right time to re-assess the potential of intensity interferometry so that
it can be taken into consideration in the design of these large facilities.
