I have a nagging suspicion we JUST had a thread on this topic, but I can't find it.
There's been a long and somewhat antagonistic discussion on an email list I subscribe to, a Nighthawk group, about plugging holes in tires.
Some members are violently opposed to it, even if the tire is brand new. Others are much more sanguine about the whole thing, and figure as long as it's a clean puncture and the tire is reasonably new it's fine to plug it.
What says Motorcycle Lounge? Would you plug a tire? Which plug(s) would you trust? Which wouldn't you trust to walk the bike home, let alone ride it? Am I crazy and you have the burning urge to tell me?