3D Motion tracking plugin from PFHoe
Motion Templates Collection
FX Factory
Boris FX Final Effects Complete
Motion plugins list at Toolfarm
Idustrial Revolution Volumetrix
FxFactory
Here's a review dated 10/10/07
AutoMotion from Digital Heaven
Sapphire plug-ins from GenArts
Continuum Complete from Boris FX
Shine and Starglow from Trapcode
Particle emitters from Wondertouch
Pro Import AE 3.0 from Automatic Duck
dvMatte Blast real-time dv/hdv/hd keyer from dvGarage
3D Flag and Stackwerks from Zaxwerks
Templates and tutorials from motionvfx.com
Free templates and other goodies from Peter Wiggins
Templates and Tutorials from a french site (requires registration)
CHV Electronics FxPlug Plugins
Some excellent tools from Special Case:
-The Collector is a great little tool for collecting and optionally zipping up a Motion project and all its associated media.
-A script for exporting an Illustrator path as a Motion shape object file
-A script for exporting an Illustrator path as a Motion Path behavior preset
-A script that exports the position keyframes of the currently-selected layer as a Motion position preset. This allows for AE-applied tracking data to be used in Motion
-A layer preset that makes video footage look like old film