Having recently taken an interest in not inhaling large quanities of sawdust while woodworking, I picked up a cyclone dust collector, which has been working great. Unfortunately, the dust collection situation on my table saw leaves quite a bite to be desired, something I gather is pretty common for contractor-style saws.
In fact, Fine Woodworking Magazine ran an article a few years ago about dust-proofing any saw. Among other things (like sealing up smaller openings in the sheet metal housing of the saw), they suggest building a box around the motor, which simultaneously acts as an outfeed extension and seals up the back of the saw so dust is collected more effectively by a port on the bottom of the saw. The box is designed to be large enough to allow room for the motor to swing as the blade angle is changed.
Although I started down that path of building a plywood box, I realized I didn't necessarily want the bulk the combination outfeed extension/airflow guiding box would add (nor did I necessarily want to spend the time to dial it all in). I also realized that 95% of the time I'm using the saw, the blade is in the vertical orientation.
So I removed the craptastic plastic baffle that barely covered any part of the back of my saw, and added velcro strips around the opening:
I cut two pieces of half-inch plywood so they would fit around the motor support, splitter, and drive belt, and stuck on the mating velcro pieces:
Installed, they seal up the back of the saw pretty well!
There's still a little bit of open area around the features, but it's drastically reduced, and dust collection works marvelously. When I do need to tilt the saw, it doesn't take much to pull the two panels off (I may yet make an alternate set that allows for tilting).