hahaha this thread is great.
yes, don't forget to tighten down the cog before you tighten the lockring. and i also am a proponent for going to an LBS and asking to get it tightened with the proper tool. it is a 5 second job and you really don't even have to take the wheel off or anything.
about a week ago the cog/ring fell off my bike in the middle of a commute. i got off, turned my bike upsidedown, and threaded the cog back on via "the italian method." i read about it here:
http://204.73.203.34/fisso/eng/schpignone.htm
then i rode by semi-working bike (very careful to not put any backpressure on the pedals) to the nearest bike store, borrowed the right tool, and locked that bastard of a ring down.
quick, easy, and free. three words i like.