xmp sidecar files- move/delete Bridge CS3

Hello

Anybody know a good way to hide the XMP files- or can they be moved to another folder? I don't suppose it is a good idea to delete these sidecar files
Is there a way for me to specify in Bridge CS3 that I do not want the .xmp files to be saved in the same folder as the images they are attached to?

How come .xmp files get saved for some of my tagged images and not others?

thanks