Project Management - Collaberation

Here's the deal.
I am about to begin managing THE project.
You know the one. the one that makes or breaks a person's career.
THAT one.

Actually, it is something like 10 medium sized projects all rolled into one.

This will be cross functional, in fact cross-company in that we will have members from 3 separate "sister" companies plus outside vendors involved.

Two topics: Collaboration ; GTD for truly LARGE projects

Collaboration:
I know there web based collaberation applications out there. Have you used one in a large project (either as the manager or as a member)? Which one? what did you like/dislike about it?
Have you used something NOT Web based? (i.e. MS sharepoint Portal server, etc.)

Communication will probably be done through email (rather than forum posts, etc.)

What I need is a good place to store, share, manage content, of the shared project documents, reports, etc. To be shared by various people not on the same LAN. (Hence the Web based idea).

GTD for Truly LARGE Projects: RFC (Request for Comments)

Here's my thoughts, please give me feedback:

My plan is to
1. Create a master MS Project file for overall reporting (Gantt, etc.)
2. Create a Folder for each "Sub-Project" (i.e. Server Upgrades, Training Plan, Software Mods, etc.)
3. Place various detailed documents for each sub-project into the appropriate folder: Detailed Task Lists, Assignment, Logs, Issues Lists, Risk Management notes, change requests, etc.
4. Have various team members use the folders for common storage of all project related materials.

We use Outlook in the company, so meeting requests, and calendar stuff will be handled that way. I know that doesn't handle a "Team" calendar concept well since we are talking about people from various companies being involved.