Hello,
Just in case some other wikipedias are interested, too: In the german wikipedia we started an experimental web of trust yesterday. It works by the "what links here functionality". A user who wants to participate creates a page [[User:Name/trust]] and lists there all the people he trusts in the form [[User:Otheruser/trust]]. By visiting a trust page (existing or not) and clicking on "what links here" you can see which people are trusting this user.
A description in german can be found at http://de.wikipedia.org/wiki/Wikipedia:Vertrauensnetz An example page is at http://de.wikipedia.org/wiki/Benutzer:Elian/Vertrauen
greetings, elian PS: english wikipedia has a page http://en.wikipedia.org/wiki/Wikipedia:Trust_network with another proposal.