Steps:
1. Open history of some phriction-document, for example: https://secure.phabricator.com/phriction/history/changelog/2011_11_november/
2. Click link "Version 1", for example: https://secure.phabricator.com/w/changelog/2011_11_november/?v=1
It's possible to add here buttons "Next version" and "Previous version" for comfortable navigation.
I think it will be very usefull.