It's like advanced yoga for your fingers I always think... BUT you will get there I promise, it does happen with practice - remember how ridiculous those barre chords seemed at first, and now you can do them? It's the same kind of process.
Also remember to keep the thumb pressing in the middle of the neck, behind the first finger, or maybe just slightly further up. This allows the wrist to drop low, so that in effect the hand is kind of reaching around the neck - it gives your little finger a fighting chance of making the stretch. When I play these kind of stretches on the first string, I find the little finger is fairly straight (without being locked at the joints) and I am not using the tip of the finger to push on the string as more normally, but a bit further towards the pad on the finger.
But I don't have very long fingers or anything, and I can promise it is possible if you keep at it, honest! 
Edited by Megi (28/10/11 12:00 PM)
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Graham, jazz guitar nut!
