Had a flat on my 84 Dodge Charger, that was one of the first cars with the low profile tires...
Had a flat.. a bus passed me and threw a rock at the tires..
found out that as long as the tires were still on the rim, then no problem, just keep going, as long as you don't do anything stupid, you pbly won't hurt the rim. I was told by several tow drivers just to make turns slowly so the tire wont' pop off. Much safer than standing by the side of the freeway.
Should be the same for bike rims. Much less weight on them.
Unless you're out on the middle of Nowhere Utah on I-15/I-70 and get a flat front tire...
then it was prudent to call for a tow truck! <BG>
Mary