Is it possible to configure Safari's search box to use google.co.uk rather than google.com? Is it possible to customise the search engines used by Safari 5.1 on Snow Leopard? I'd like to get it to use google.co.uk rather than google.com for searches. I've found a couple of old posts (including this one which doesn't seem to apply any more) but nothing very recent.
the query string is defined in : 

~/Library/Safari/Configurations.plist.signed


but the file is signed and cannot be edited without being replaced by safari.

Also, it seems that every time you use this search bar, Safari hits This file on apple.com which can make one assume that Safari compares the 2 files and replaces the local one when needed.

I think your only options are via extensions or another browser