I just use the standard calibrated baby bottle.  Holds about 10 oz, has a mark every ounce, is easy to pour, and lid seals tight.

Hi Bill,

I knew I must have missed something by not having kids (aside from having someone to cut the grass for a few years) :-)  

Thanks for the comments.  I think I've decided to just use the scale on the side of about a quart sized bottle, though I haven't decided if that's going to be a 2-stroke oil bottle, or an MMO bottle.  No shortage of opinions on the RX-7 sites...