We make it simple in my organization, unless it is a malicious site or other security related category (e.g. anonymizers), HR owns who can surf what, as it is more of a time management issue than an IT issue.

Definitely check out WGU. I earned my M.S. in Information Security and Assurance, my wife earned her Post-Baccalaureate in Elementary Education, and my sister earned her B.S. in Marketing Management. I've had numerous employees enroll with WGU after having been made aware of it. They are non-profit costing the student only ~$3,000 per six-month term and is regionally accredited by the Northwest Commission on Colleges and Universities, one of the major accrediting commissions recognized by the U.S. Department of Education. Moreover, the College of Information Technology has "slip-streamed" industry certifications into their programs (pass the cert test, pass the class)... fantastic!

Given the submissions, I'd be disappointed if Slashdot changed their logo given all but one appear to be of substandard quality (IMO). The only one I would even vote on would be Erik Berglund's, as it has it simple but effective change to the existing logo (adding a slash to the "o").

It is simple... users contribute simply by using... which increases demand. Without demand, there would be no product. Thus, by someone using an open-source product, they are contributing to the demand. The higher the demand, the more opportunity for said product to evolve.