It's easiest if I post an example for you to see: http://www.google.co.uk/search?hl=en&q=Theatre+Auditions&meta= How does that happen? I already use Sitemaps and don't get this for phrases I'm #1 for.
Thats the first time i have ever seen that. I think you should check out their FAQ / help center and see how that works.
I am seeing it on sites where highly optimized sites with PR hit little or no competition. Can anyone else confirm this? Eric