Marketocracy's investment clubs let you do is pit your investment skill against your other investment club members, and against the rest of Marketocracy's members. It is free.
I have been running a mock mutual fund portfolio on Marketocracy for a couple years now (see results from inception July 2000 to Dec 2003 an annualized return exceeding the S&P 500 by 12% annually and the return for 2003 was 64% versus 26% for the S&P 500 and 50% for the NASQAD Composite.
As of 31 Mar 2004: beating the S&P 500 by 13.6% annually, since inception.
As of Jan 2006: beating the S&P 500 by 5.5% annually (the fund is up 5% and the S&P for the same period is down .75%.
Serious investors are invited to apply to join the club. Members of the club study leading investors such as Buffett, Livermore, Darvas, O'Neil, Templeton, Soros, Lynch, Neill, Loeb, etc.. The focus of the club is not on any one style but rather guided by an intense study of the stock market and applying investment theory. The club aims to build a community of successful, investors who share a desire to learn from each other. Club members are committed to advancing their intellectual knowledge of investing and then applying that knowledge successfully in the market.
The first step to joining is to signup for a Marketocracy account. If you already have an account on Marketocracy, then you can simply use the "join a club" option to apply for membership.