is there a hole on the inside of the tire, or no?! if not, just dismount the tire and crazy glue the hell out of the outside hole, then let it dry for about 15 minutes and re-mount it. don't worry about any excess glue on the tread, the road will wear it away smooth after the first ride on it...
i've also heard shoe goo works well, but i've only done it with crazy glue. you may be able to find a how-to with shoe goo on youtube though...