Guest what?

So I was just reminded that I usually do 'guest' something or other in the summer. I've done guest toes a couple times. Guest gardens. Guest desks. What would be something fun that you'd like to see your favorite author guest with? Guest computer desktop? Get a peek at their screensavers or current work in progress? Guest book shelves? Get a glimpse of their favorite reads?

I'm open for suggestions!
M