Was looking around for a non-keyed gas cap for my TE610 and came across this http://www.advrider.com/forums/showthread.php?t=472509 (among others). I liked the fact that it allows you to hold a little more fuel by plugging the vent holes and using a stubby breather hose. Pricey at $125 + $10 shipping, but the fit and finish is top notch.
Very cool I’m just going to throw this out there; For those who had enough of the two keys yet do not wish to lose the stock gas cap look Nesbocaj did this excellent thread on how to unkey the gas cap key http://www.cafehusky.com/forums/showthread.php?t=2956
That is very clever! My stock cap fit so poorly on my I.M.S. tank that gas would seep out around the base when full, so that also made me choose a new unit.