Differential methane-band imaging (Smith 1987, PASP, 99, 1344; Rosenthal et al.
1996, Nature, in press) is an important tool for brown dwarf and
superplanet detection. Subtraction of a near-infrared methane-band image from
an image taken in the adjacent brown dwarf continuum readily reveals Gl 229B-like
brown dwarfs, as they are seen to modulate in flux while all other objects,
including primary stars, null out. We present differential images of the Gl 229B
system taken at the NASA Infrared Telescope Facility (IRTF) in August, 1996, as
a demonstration of the power of this technique. Preliminary results for 65 G, K,
and M stars imaged at the IRTF will be presented. We will discuss future
observing strategies using the IRTF, Keck, HST, and other telescopes.
