The only one I have actually seen is the <a href="http://www.themodernantiquarian.com/browse.php?site_id=635">London Stone</a>, arrogantly caged in the outside wall of a bank. It's a sad state of affairs, and no mistake... *sigh!*
I was working near it a little while ago, and could not believe what a travesty it was! According to <a href="http://www.themodernantiquarian.com/browse.php?site_id=635&show=all+news#post-7349">recent updates</a>, it is to be moved AGAIN!!!
Still - it's London, innit?
;o)