[Lizard]

We plan to add custom data columns in a future version, which would allow you to create a "Assigned To" column and track things that way.

Meanwhile, I recommend creating a context for each person to whom you assign tasks and putting their tasks in those contexts. I think we could add custom columns to contexts as well as projects and actions. Meanwhile a hack for having the contact information in each context would be to create a Contacts single-action group and create an action in it for each person, with the notes containing all their contact info. Then assign each contact "action" to its related context and when you look at Joe's context, you'll have info on how to contact him right with all the things you need to talk to him about.* Email addresses and phone numbers in notes even become clickable links in OmniFocus for iPhone.

*I just thought of this. It may only sound good in theory and not work well in practice.