This "hack" uses 37signals' Campfire software as a great note-taking solution for class, meetings, etc.
I feel that Campfire's excellent real-time record keeping ability, multiple chat room (or page) features, access options, and file management tools are ideal for not only the GTD system but point-of-contact record keeping that lets you integrate easily into 37signal's other software such as Basecamp project managing.
To use Campfire & GTD, it can be set up very similar to how Backpack works. Using chat rooms as pages, etc. If you look at the second link below, it outlines how to use GTD w/ Backpack. A few simple changes can be made to adapt this method to Campfire quick and easily:
For whatever project you choose, aptly name a new Campfire account. In the Backpack version, tags are attached to each page to give you an easy way to see where everything is. For Campfire, instead of using tags, create a new chat room (as with every 37signals product, paying for it gives you more room to grow) for things like "@home" or "@work". You can log-in to your Campfire and see the activity in each of these sections and keep a real-time record of whatever you like inside each chat room. Giving other people access as members or sharing a Campfire page can increase productivity as well. The topics feature can also be used as a tag-replacement, giving more detail to whichever room you are in.
Not only is Campfire an excellent project collaboration tool, but many higher education students will have this luxury at their disposal in the coming years to tackle fast-paced classwork (big-time "told ya so" to me for figuring this out less than a month before I don the cap and gown).
The first link below outlines a great way to take notes for class that can be made even better in Campfire. Instead of having to set-up a master schedule and link pages together, etc., you can start with a fresh Campfire account for each semester. At my school, 5 classes a semester is the normal load, so Campfire's free version works perfectly. For example, my new Campfire account could be called "fall06.campfirenow.com."
From there, create a chat room for each class with it's name (i.e. COM 460: Adv. Multimedia Comm.), these rooms act as pages where your notes for each class will be kept. Along with any relevant documents, files, etc.
Since Campfire logs the exact date and time each time you enter a room or "page," it makes for more intuitive note-taking. You can just type whatever the teacher is saying or notes you want to take. Think of Campfire as your big 5-subject notebook in the sky that lets you take your notes everywhere there is a net connection. Campfire logs the time and date of whatever you type and you can search for something specific in it's excellent transcript section. A lot faster than flipping through endless pages of blue or black ink.
Someone from you class need the notes? Want to share your notes for a group project or double-check with a professor? Either share whichever Campfire page you want or give anyone with an e-mail address member access to the chat rooms. A lot more simple and effective than meeting a person all the way across campus, 11pm on a Monday night. If you have to share a room, locking others that contain sensitive information is easy. Also, you can add topics to each room or page to give a more detail to each class.
Similar applications, using Backpack, can be found here:
Many practical, right-out-of-the-box uses for Campfire: http://www.campfirenow.com/examples/