I've just converted this into a 'customization' (Settings > Customizations) so it will add a link to the page to do it rather than as a bookmarklet.
name: FB Clone
description: Adds 'Clone' links to left hand side
author: apfrod/Rich Armstrong
version: 1.0.0.0
js:
if(goBug && goBug.ixBug !== 0) {
var clone = '<p><a href="#" id="clone_new">Clone as new case</a></p><p><a href="#" id="clone_subcase">Clone as subcase</a></p>';
$('#bugviewContainerSide').append(clone);
$('#clone_new').click(function(){
window.open('/fogbugz/?command=new&pg=pgEditBug&ixCategory='+goBug.ixCategory+'&ixProject='+goBug.ixProject+'&ixArea='+goBug.ixArea+'&ixFixFor='+goBug.ixFixFor+'&ixPersonAssignedTo='+goBug.ixPersonAssignedTo+'&sCustomerEmail='+escape(goBug.sCustomerEmail)+'&ixPriority='+goBug.ixPriority+'&sTags='+escape(goBug.ListTagsAsArray())+'&sEvent=See case '+goBug.ixBug+': '+escape(goBug.sTitle)+'.'+escape('\n\n'+document.getSelection()).replace(/%25A0/ig,' ').replace(/\+/ig,'%252B')+'&b=c');void(0);
});
$('#clone_subcase').click(function(){
window.open('/fogbugz/?command=new&pg=pgEditBug&ixCategory='+goBug.ixCategory+'&ixBugParent='+goBug.ixBug+'&ixProject='+goBug.ixProject+'&ixArea='+goBug.ixArea+'&ixFixFor='+goBug.ixFixFor+'&ixPersonAssignedTo='+goBug.ixPersonAssignedTo+'&sCustomerEmail='+escape(goBug.sCustomerEmail)+'&ixPriority='+goBug.ixPriority+'&sTags='+escape(goBug.ListTagsAsArray())+'&sEvent='+escape('\n\n'+document.getSelection()).replace(/%25A0/ig,' ').replace(/\+/ig,'%252B')+'&b=c');void(0);
});
}
I've also added a custom field to this using the following to get the field, and adding the string to the url:
if ($('label[for=idBugViewDialogItemclientS15]').length > 0) {
goBug.clientS15 = $('label[for=idBugViewDialogItemclientS15]').next().html() || '';
goBug.clientS15 = '&clientS15=' + goBug.clientS15;
}