Hrm Dave that doesn't seem to work. Maya is telling me that two separate poly meshes have to be selected to boolean them. So I can't combine them and then boolean difference them.

Update: I got it to do what I wanted to do, but the method behind it is not ideal. All I ended up doing was creating a duplicate object a local 0,0,0 and then booleaned the two objects. The the original is deleted, while the booleaned duplicate remained.

This doesn't always work very well, anyone got a better way to do it?