I don't think this is realistic, but let me make sure I understand what you want. You start out in GBrowse at FlyBase, and then you go to a Stock Collections GBrowse, which is on another server (actually, I don't think the location of the second server matters). One instance of GBrowse doesn't know anything about another. What you could ask the FlyBase and Stock Collections people to do is integrate their GBrowse instances better. For example, if you are going from FlyBase's GBrowse to the Stock Collection, FlyBase could write their GBrowse so that links from it to Stock Collection would carry along the information about the source sequence that was looked at when at FlyBase.