http://www.usno.navy.mil/pao/press/EtaVirNPOI.jpg

"This image of the triple star system Eta Virginis is the first ever
made by an optical interferometer using the combined beams of 6
separate telescopes. The closer pair of stars have an angular
separation of about 5.4 milliarcseconds, equivalent to the size of
a U.S. penny coin viewed from a distance of 800 kilometers (500
miles). This level of detail would require a single monolithic
telescope mirror in excess of 50 meters in diameter. U.S. Naval
Observatory photograph."

Isn't it amazing the sensitivity that we are reaching. It's a far cry from the days of the first telescopes. Thanx for the info thed, most interesting.