In reply to rhysowen:
Not to be a tosser and treat this like a serious issue, but some arguments against cord and for a buckled belt:
Way easier and quicker to put on and take off - approx. 2 seconds versus 8 seconds for a double granny knot/2754 seconds for a double fisherman's (which is the only way you'll ever truly trust the knot to not come undone with regard to Martin's tale of woe). Also easier to clip onto the outside of a backpack and scoop up off the ground without having to carefully grab both ends of cord/tie a knot in the cord when you take it off, lest you grab one end and the chalk bag slides off.
If you lend your chalk bag to someone, very unlikely that the strap won't be long enough to go around their waist. When I used cord, however, I had it just the right length to go around my midsection (roughly the same as Ondra's after a kale/dioralyte binge), and so anyone else who wanted to use it had to suck in and/or make themselves vomit prior to use.
Lastly, and most importantly; while accessory cord is, inarguably, more useful than a bit of shitty, non-rated webbing connected by a plastic buckle, who will ever actually be in a situation where they need it? Really think about this. 84.7% of the climbing in this country occurs at Stanage anyway (based on a survey conducted by the Bureau of English Nice Days and Expeditions Research Society), and anyone who dares to venture into terrain where anything even remotely unexpected might happen does so equipped with prusiks, extra slings, and cord for the specific purpose touted by posters above.
In conclusion, then, while cord provides greater functionality in terms of emergency situations than a belt, it does so at the expense of general usability. Moreover, for the vast majority of climbers, the possible benefits of having one additional measly bit of cord in an emergency situation are outweighed by the thousands of hours lost in fiddling with said cord - equivalent to between four and six extreme ledge-shuffling leads at Stanage.