With a wireless ethernet card, a laptop and some basic software savvy, you can get on the Internet for free from almost anywhere in downtown San Francisco. In fact, you can get a lot more than free Web surfing. You can waltz unhindered into dozens of corporate networks and access passwords, databases and private e-mail.
<p> Not all public wireless networks are there by accident, a number, such as <a href="http://www.seattlewireless.net/">Seattle Wireless</a>, <a href="http://www.pdxwireless.org/">Pdx Wireless</a> and <a href="http://www.consume.net/">Consume</a> in London have been set up as community projects. </p>