Originally Posted by swjohnsey
I do carry a spare plug on long trips (more the 10,000 miles). Instead of carrying it in a giant plastic case, I gap it, put anti-sieze on the treads, put it back in the original box with the cardboard ring around the treads and then wrap the box in duct tape. You now have a plug that you will never use and a handy supply of duct tape.
I don't mean to be antagonistic, but just in case you, or a n00b reading your post overlooks it: something to consider is that whilst more compact, the method you describe probably won't protect it from water. My main reason for carrying spare spark plugs is for when the existing ones get wet; either in a river crossing, or in the case of my SV, water-ingress into the front plug during prolonged rain (or a dealership cleaning the bike with a pressure washer
If it's just a quick dip, or you're in hot climes, you might get away with a quick spray of WD40 and taking it out to dry for ten minutes. If it has been properly soaked (botched river crossing/floods) this may not suffice. Either way, a properly waterproofed spare plug carrier like the acerbis ones will allow you to get back on the road sooner.