Tonight (Tuesday evening) I had another pass, a low west pass at 35 degrees altitude this time. And....it was invisible, to the naked eye at least.
On April 27th, Russell Eberst observed an unidentified object that moves in the same orbital plane as NanoSail-D and appears to be "something" from the same launch (see also here). It was subsequently observed by a number of other observers (and perhaps earlier, on March 3, by Greg Roberts), and yesterday I photographed it:
Another object observed this evening was Lacrosse 5 (05-016A).