Well I got my first image of a MACHO (I assume either a Black Hole or Neutron Star) this weekend when I successfully took photometry on a microFUN target (gravitational microlensing of a galactic bulge star). In the 10 hours I followed the target it's magnitude increased from mag 15 to mag 13, peaking a couple of hours later.
Still Image here:
http://www.david-higgins.com/Astrono...croFUN2008.htm
Movie here:
http://www.david-higgins.com/mb225.mov (QT movie 608kb)
Just watch for the brightening star in the centre of field.
What you are seeing is the MACHO passing almost directly in front of a background star, increasing it's brightness through gravitational lensing.
Cheers