SVN and Trac, running on poppins, uses LDAP for authentication. I've created user accounts for most of PLC, if not all. There are no API calls to grab passwords from the PL API and making a backdoor to sync PL passwords with LDAP passwords doesn't really appeal to me. So, in order for PLC to log in to trac, please do the following:

 $ ssh root@poppins

# passwd <your username>
Changing password for user tmack.
New UNIX password:
Retype new UNIX password:
LDAP password information changed for <your username>
passwd: all authentication tokens updated successfully

You should now be able to log in to http://svn.planet-lab.org/ and create/edit content.

Also, this same password can be used to check in over webdav (once I get signed SSL certs from GoDaddy).