The Freakonomics blog has this good post:
Todd’s idea: The site would function as a recruiting network, giving students and corporations an entirely new dimension of access to one another. Corporations would post tasks, real or simulated, for students to work on. These tasks would be organized by subject area or industry, such as computer science, mechanical engineering, journalism, marketing, web design, etc.
Students would create individual or team profiles and work on selected tasks, submitting their completed work in the form of text, images, videos, power point, audio, or any other format that can be uploaded. Companies will have the ability to rate submitted work, allowing students to accumulate a “work score.”
The benefit for the corporation would be their new outlet to recruit students who have a proven ability to excel at the type of assignment they will be faced with on the job.
They will also find that they have a large audience of well-educated students who are quite motivated to impress them with their submissions.
The funny thing is, you can do this already, and without the competition from having all the other students know about it. Find someone you really admire or respect. Email them. Describe your skills, how you can help them, what you have to offer. Link them to your blog full of quality posts. Then offer to work for them for free. If they accept, take whatever task they give you and knock it out of the park. Go the extra mile. Make it your most important task for the day, or week, or month. Do the work quickly and efficiently. Then, when you're done, email the person and say that it was a pleasure working for them, and you'd love to help them out in the future if they have any other cool projects lined up.
Now, do this once a month for three years while you're at university, then see how many job offers you get when you graduate. Such is the power of the internet.