CNMAT's OpenSoundControl object extends MaxMSP 4.5+ to support OSC bundles.
Additionally, the OSC-timetag object deals with timestamp generation, transformations and operations, and the OSC-schedule object handles bundle scheduling from timestamps.
Additionally, the OSC-route and OSC-unroute utility objects are useful for parsing and constructing address patterns:
Other misc stuff:
The slipOSC object deals with OSC transport over a serial line with SLIP encoding. http://cnmat.berkeley.edu/downloads
OSC wrappers for various controllers: http://cnmat.berkeley.edu/library/max_msp_jitter_depot/modules_building_blocks_mmj_depot/controllers