A tool i spend a lot of time with at work is Microsoft Outlook, as i guess it is with many of you as well. Often, i get mails that translate to initiating tasks. For that, Outlook can be used to create a Task, based on that mail, or set a follow-up flag on the mail, denoting that it's something to do. The vital difference here is that the flagged mail is the task, whereas a Task created from a mail is a copy of that mail. Finishing the Task will not have any input on the mail that was the source of the Task (before you get all weirded up, a Task is the Outlook-specific representation/implementation of a task, a Contact is a contact entity in Outlook. And so on).
Often, however, a single mail does not constitute the full communication and involvement of a task. The GTD school of thought calls any task with more than one action a project, which is fine by me. A project will usually include a minimum of two persons -- the requestor and i -- but more often have other stakeholders included. These stakeholders can be represented as Contacts in Outlook.
What i would really appreciate is to quickly and painlessly whip up a Project, which, if created from a mail, is tightly bound to the mail that the Project came from. A Project can have many tasks (or Tasks, if you will) and many Contacts. All communication, mail mostly, but could be IM as well, would be part of that Project.
I'm sure this could be done with existing tools -- OneNote or Groove perhaps -- but i don't know how. Do you? How do you manage your projects.. eh, Projects?