I've got one other little trick Mbo, but it's another wierd approach (like the Bb6 in the other thread). Once again folks, let me emphasize there's no substitute for learning the standard fingerings that you can find in chord books. These are supplementary approaches that can allow you to play MELODIES plus a part of the chord when you're using a right hand syncopated bass. They're also useful in the chord-melody style of a Joe Pass or Eddie Lang thing.

Play a normal C chord. Now try and flatten the middle finger just enough to fret the third string at the 2nd fret. You've got C6. Move it up three frets...Eb6.

All these weirdo chords are tricky, but none is impossible. I learn 'em while watching baseball games!

Rick