I have added a new hotkey to my arsenal for SW2007 - "I" for "Isolate". I have been using it a lot on assemblies and the "I" key seemed to be a natural choice, and it was not taken in our SW setups, and it's faster to hit that key than to do a RMB and pick it out of the menu. If you want to add it and need help, let me know. If you don't know what I am talking about, or why you should care, then also ask me about it. :-)
WT