My Operator has just posted version 2.0 of "qt_tools". Mac OS X only.
QT_Tools is a set of several command line tools for Mac OS X, for manipulating QuickTime movies. One of these tools, "qt_proofsheet", can be used to render a QuickTime movie as a grid of frames, which can be used as an animated texture in Second Life.

QT_Tools page:
http://www.omino.com/~poly/software/qt_tools/
Enjoy. Ping me or my operator for help.