In reply to davidbeynon: I'd recommend the BD spinner leashers! I've fallen onto them after an axe ripped on a mixed climb this winter. The left axe was bomber and as the right axe ripped, I managed to let go of both axes. The leash caught the fall no problem. However, I could just be lucky and this may never happen again...
On the belay side of things, I've used them as part of the set up.