I would suggest that each URL (at the bottom) have a unique ID appended, where the ID is different for each subscriber and each message. This will prevent multiple voting, and allow people to change their opinions. The IDs should not be predictable, to prevent forgeries.
Newcomers to the list get any letter received by any of the most
prominent Extropians (MPEs) using the system, a list which should
consist of Max More, Lee Daniel Crocker, and Anders Sandberg. Filtered
archives would contain all of these letters, minus any that were marked
"down" by an MPE, unless at least one MPE marked them "up".
Each day, a member should receive an email containing the subjects and authors of all filtered emails. These will contain links to the CritMail'd messages, again incorporating a unique ID, so that the resulting page contains the unique ID, and thus the subscriber can vote on those messages.
That's the expensive version. The simple version, which would probably work well enough to catch the cash, is to have MPE-filtered-extropians and unfiltered-extropians. The main motive for using the expensive version is that it would constitute a nice advance in an important technology.
Final advice: OpenSource it, use Java if you can, and be sure to agree in writing whether the project requirements are worthy of the $10K/year.
-- firstname.lastname@example.org Eliezer S. Yudkowsky http://pobox.com/~sentience/AI_design.temp.html http://pobox.com/~sentience/sing_analysis.html Disclaimer: Unless otherwise specified, I'm not telling you everything I think I know.