  We searched for eclipses of two millisecond pulsars, PSR J1807-2459 and PSR
B1908+00. These pulsars are in very low mass binary systems with orbital
parameters similar to those of eclipsing binaries. Observations were made with
the GBT at frequencies as low as 575 MHz. No eclipses were detected in either
system. Observations of well-established eclipsing binary J2051-0827 found
eclipses to be substantially weaker than previously seen, with the pulsar
detected throughout the eclipse region at 575 MHz and with an electron column
density an order of magnitude smaller than previously measured.
