dmusicant I've had some ideas of my own for making raingear from those trash bags. I have some 55-gallon size in 3 mil plastic. One thing I thought of is making a hooded garment, using one of the bag's square corners for the hood. Make a cut somewhere like 8" inches or so from the corner, such that it becomes an opening for your face. This means turning the bag 90 degrees from the way you've done yours. Then do the armholes, sleeves, etc.

I also have an idea for using those bags to make a two-piece bottom-half rig, but haven't tried it yet. Not sure if it would work on a bike.