Though commonly believed to be the same thing, 90 miles an hour tape is different from duct tape. I was lucky enough to come in contact with quite a bit of this stuff through a crazy "I only shop at Army/Navy" type. Its usually beige, thinner than duct tape, and unlike duct tape, it can withstand speeds of up to 90 miles an hour.

A few things to note about duct tape: If you want it to stay on cloth (duct tape patches are fun), run a hair dryer on high over the duct tape, first straight on from the front, and then from the back of the cloth, which will melt the adhesive and therefore make it stay more permanently on the cloth. (It does withstand the wash cycle, I can tell you that much)

If chewed for a long time, it gains the consistency of ABC gum. (No suggestions on that however, since that tip comes from a friend)

And last but not least, permanent marker (Sharpie) is not permanent on standard duct tape, and will rub off quite easily. I'm told that paint pens are more hardy when it comes to duct tape decoration.