I ran the GNR on Sunday and on the start line had the "Local Hero" theme song in my mind which was very motivating (no ipod on!), but as soon as I crossed the line it went out of my mind haha, ended up humming a James Bond theme song instead for the first few miles then talking the general randomness with other runners as you do!
Hope you enjoyed Wolverhampton, I looked at doing it last year but it's tended to clash with the late September/October marathons/training.
There was a successful thread on this a few years ago - someone simply ran the organisers and asked. It'll be around on the forum somewhere if you have time to look. The numbers were basically something like 20,000 ballot, 10,000 club/GFA/sponsor's and company partner's places e.g. international tour agencies, and the remainder (up to 10,000) as golden bond.
Ah - the first race without music, always a tough one! Best get used to it, many ban them now! I almost didn't do our local half 2 years ago because they were very strict on iPods and I'd always ran with music before, but so glad I took the plunge and went without. I compromise now - music on solo long runs and marathons (if allowed) and without for club sessions and other races (or races such as GNR, VLM where support is awesome). Less faff without as no wires bouncing about and earphones popping out.
The other (extreme!) way to get used to running without them is to do a triathlon! You start off in the water so no headphones there, and then on the bike you've got the rush of the wind in your ears to listen to, so by the time you reach the run you don't even realise you don't have music :O) so now in a running race I just chat or think my own thoughts, usually have a song going round in my head. Although on a banned race, I don't always find it easy, I did a 20 mile race last spring and found it tough as it was a hard race anyway and I'd been doing so many solo training runs all winter! And a few months ago i planned to run a half with 2 friends and chat (ipods were permitted if quiet) however I had a bit of an injury and fell way behind, only to feel hugely demotivated and got out my ipod to distract me from my slowest ever half ;0(
Slightly annoying you only just found out though - maybe prepare yourself for races banning the ipods at the last minute and try not to assume they'll be allowed! Just don't do what I almost did and not sign up for a could be a brilliant race purely because of the no headphone rule.
Good luck - just chat away randomly or listen to people's gossip around you ;O)