  Experiments are in progress to prepare for intensity interferometry with
arrays of air Cherenkov telescopes. At the Bonneville Seabase site, near Salt
Lake City, a testbed observatory has been set up with two 3-m air Cherenkov
telescopes on a 23-m baseline. Cameras are being constructed, with control
electronics for either off- or online analysis of the data. At the Lund
Observatory (Sweden), in Technion (Israel) and at the University of Utah (USA),
laboratory intensity interferometers simulating stellar observations have been
set up and experiments are in progress, using various analog and digital
correlators, reaching 1.4 ns time resolution, to analyze signals from pairs of
laboratory telescopes.
