From Adam Holt:
Regardless of the fact I was talking at length with Russian support volunteer Nina Stawski last night — this is a critically important participatory-mapping precedent we need to study and learn from — I used them in 2006 and am Amazed they have not yet been clobbered/absorbed by Google 😉
“WikiMapia is a privately owned, online map and satellite imaging resource that combines Google Maps with a wiki system, allowing users to add information, in the form of a note, to any location on Earth. Users may currently use this information for free; however, contrary to popular belief, Wikimapia is not creative commons and they make explicitly clear in their terms of service agreement that they retain the right to impose fees or usage restrictions at any time. Inspired by the success of Google Maps and Wikipedia, two Russian Internet entrepreneurs Alexandre Koriakine and Evgeniy Saveliev launched the website on May 24, 2006. Its aim is to “describe the whole world”. It now has over 13,600,000 places marked. Although registration is not required to edit or add to WikiMapia, over 996,253 users from around the world currently are registered. All content uploaded by users is currently made available for non-commercial use through Wikimapia API.”
The entire http://en.wikipedia.org/wiki/WikiMapia article is worth pondering carefully; just 1 excerpt for now:
Users can vote in favor of or against other users’ contributions, thereby allowing users to rise in status among the community. There also is a user statistics and ranking board which automatically ranks users based on their contributions. However, vote tallies and user statistics have no impact on a user’s user-level.
 User accounts and levels
Optional user accounts were introduced in October 2006. User levels and permissions have evolved over time in response to the need to control vandalism or abuse. As explained in the WikiMapia FAQ, there are three user-levels.
- User Level 0 (UL0): Level 0 is the default user level assigned to all new users. UL0 are able to add places, edit existing places, and use the personal messaging system. New users are temporarily prevented from posting in the forum.
- User Level 1 (UL1): Users are automatically upgraded to UL1 after a few days. In addition to the regular UL0 functions, UL1 users are able to change polygons (place outlines), add roads, add rivers, add railroads, delete places, and contribute to the forum. The vast majority of Wikimapia contributors fall into this category.
- User Level 2 (UL2): A few hundred registered WikiMapia users have been granted Level 2 access. UL2 permissions include functions which are vital to maintaining site security (such as the ability to initiate ban proceedings on vandals) and anti-vandalism efforts on the map itself (such as the ability to delete a greater number of tags, to protect tags against editing by unregistered users, and to quick-delete certain tags).
 UL2 status
UL2 status may be one of the most misunderstood aspects of WikiMapia’s hierarchy, in part, because the process of promotion remains mysterious to most new users. Level 2 permissions are granted solely at the discretion of WikiMapia Administrators (or site owners), and have been revoked in a few instances. Although Wikimapia Administrators have historically taken recommendations by senior users into account when promoting new users, they have also occasionally acted unilaterally to demote UL2 users.
 Clutter and filtering
In some areas of the world with out-of-date or very expensive mapping, such as India, WikiMapia growth has been phenomenally rapid. This rapid growth brought problems of its own, however. Urban areas became covered with thousands of overlapping rectangles marking the positions of private residences, but there was no provision in the WikiMapia interface for distinguishing those residences from places of public interest.