Joblot:

This is exactly why I said on a previous post, tell the people who know you prepare and will be prepared that you will not help them. The shock of having a friend or aquaintance who could help telling them they will not help will induce more participation on their part, or at least when the excretement hits the oscillating member, they will not bother you out of embarrassment or because they know you will not be there for them.

Tough to do, but better for them and you.

Bountyhunter