I'm using the Mio Link HR Band (this one: http://www.mioglobal.com/Mio-LINK-Heart ... oductID=14
) in combination with my Leikr and it's working fine.
But keep in mind, in my opinion the HR band is not as accurate as HR chest straps are. Not a big deal but if you are doing a lot of interval based workouts the HR values are often a little bit behind the values of a chest strap.
But all in all (looking at the recorded HR curve afterwards) it seems ok, so maybe the noted deviation is more academic nature