[Lutin]

I have a context 'WaitingFor'. It has a few sons for key people in my life, like 'WaitingFor Bob', 'WaitingFor Alice', 'WaitingFor Nestor'...

I synchronize OmniFocus with iCal.
From iCal, I've published the calendars to a webdav server, and communicated the link.
That way, they have a list of what I've asked them and that I'm waiting for.

One minor drawback:
If I'm waiting for a package that someone needs to send me, and I know it won't arrive before 2 weeks, I usually put the start date 2 weeks ahead to keep view uncluttered. As the task is not available, it don't show up in the calendar of the remote person.

Note:
I always ask personally (face to face, IM, mail...) before adding a task to a WaitingFor context. First, I have a task like 'mail bob asking to do this'. Once completed, I add an other task in the WaitingFor context, to keep track of it.

I would find rude to get tasks pushed to me without initial consultation. Please keep that in mind if you integrate a delegation system into OmniFocus.