The Inside Flyer article is a good resource to dealing with the issue.

Here's my question (I may save it for Randy's live Q&A next wk: What if you don't ahvea spouse and want to leave the miles to a friend?)

What I did do is give my lawyer a copy of all my airline/hotel/Membership rewards and Diner's Club accounts and teh passwords. I trust him. He's not my lawyer; he's my friend and steak and wine buddy.

Hopefully he won't have to do anything with this for a very very long time!