Research for Virtual World Concept

I found some other virtual worlds that are similar to my concept. Here are several helpful links that review each virtual world. Although the last one isn't a true virtual world, it has many elements similar to my concept and researching it might help.

Trackmania

http://www.trackmania.com/tm/index.php

http://en.wikipedia.org/wiki/TrackMania

http://www.gamespot.com/pc/driving/trackmania/review.html

http://pc.ign.com/articles/528/528114p1.html

Upshift Strike Racer

http://strikeracer.gpotato.com/

http://en.wikipedia.org/wiki/UpShift_StrikeRacer

http://pc.ign.com/articles/800/800122p1.html

http://www.mpogd.com/news/?ID=3046

Mario Kart Wii

http://en.wikipedia.org/wiki/Mario_Kart_Wii#Nintendo_Wi-Fi_Connection

http://www.gamespot.com/wii/driving/mariokart/review.html