There is technically no way to transfer an ADR, but I was able to pick up Chef Mickey's through coordinating an ADR cancellation with another DIS'er a few days ago. We did this online.
I trolled the swap post and found one that they planned on canceling and PM'ed the individual. They got back to me and coordinated the time they would be cancelling this specific ADR.
By doing this, I was able to pick up the exact time/date of the one that was cancelled (so I'm sure it was theirs).
Things to note:
1. Party size probably must be the same (If swapping with a party of 2 and you need 3 or 4, you might not be able to get it)
2. Do this late night when Disney Dining is closed! (Because it is unlikely anyone online would be looking at that exact time you're going for at the exact time you coordinate the cancellation via PM's.)
3. Obviously, you must do it online since Disney Dining is closed.
Good luck!
Forgot to mention: I did try to coordinate a cancellation during Disney Dining business hours where a nice DIS'er called in to cancel an ADR while I called at the same time. I didn't get it! :-( I think it was because a CSM could see it pop up and grabbed it for someone on the phone. That is why I think you should do this online. Online it was very easy (and no toll call to WDW!)