I often store information about people with whom I collaborate on a task. The 'tags' field is useful, but tags related to people (bill, henry, sam) can get cluttered with tags related to things (bicycle, home, shopping). The 'give to' field is useful for storing information about people, but requires an email address and can result in confusion when that person receives an email with information that is pertinent only to me.

A useful field would be for 'collaborators'. This field could be similar to the 'tags' and 'give to' fields, but would store information about people without requiring an email address or sending an email.