I got a replacement key sent from a dealer last week after losing my one. Got charged £17.60 for it to get sent out in the post. A bit dear for what it is but a lot cheaper than getting the current bolts drilled out I'd imagine.
Was relatively straight forward to get but had to fax a copy of my V5 to them and had to keep ringing them up as they were very poor at calling me back when they said they would!
Having got it now I've just taken my locking wheel nuts out and put the standards back in, don't see the point in locking wheel bolts these days really, they stem from a time when alloy wheels were rare, most cars come with them as standard now so who is going to go to the hassle of stealing a set off your car.