Several observers in Australia and The Philippines observed a transit of Io across the disk of Jupiter yesterday (Universal Time). The images some of these observers acquired are posted on the ALPO-Japan website. Anthony Wesley acquired an image just prior to the transit showing Io's shadow on Jupiter's cloud tops. Christopher Go acquired two images showing Io against the cloud tops of Jupiter. Io's reddish coloration is quite visible. Tomio Akutsu acquired similar images, though he also acquired images in other filter like in the UV, near-IR, and the 889 nm methane band. Io stands out quite well in those last two IR filters.
Link: Jupiter Image 2008/03/16(UT) [alpo-j.asahikawa-med.ac.jp]