Yeah one would think its crazy to do but it can be done for certain applications. One of the .toyota towing brochures (pdf's) phantom posted in the tow garage even show the tacoma bumper as a hitch point.
On my 95 Toyota truck (pre gen1) I towed my enclosed two place snowmobile trailer all the time off the bumper & this was before Toyota even offered a factory tow package. The chrome bumper was not much different than what's on my 06, three holes, one for the hitch ball & the other two you could rig up eye hooks. A lot of folks did it that way. Granted dinging your bumper was much easier & no way would it tow what our trucks are capable of now especially with the factory tow pak.
Personally I chose to get a frame mounted hitch because I swap out different drawbars 2" or 1 7/8'. On the bumper, that is a pain in the butt. Plus the drop works well with my trailer height & weight towed.
So I guess the question for the OP is whatcha towing??