This Friday, 7pm entry, first come, first served unless you have a guaranteed entry via the O2 newsletter (see above link) and see Joss Stone for free.
You don't have to be an O2 customer to go or to get the O2 Music Flash emails. No idea if it is too late to sign up or anything, but you could just go and queue if you want to?
*This has been a public service announcement*
Joss Stone.com