Peter Thiel, a high-profile Silicon Valley entrepreneur and investor, has launched his third major investment fund, with $402 million. Thiel co-founded PayPal (acquired by eBay (EBAY) and was an early investor in Facebook (FB), LinkedIn (LNKD), Zynga (ZNGA), Yelp (YELP) and Yammer, among others. The new fund, Mithril Capital Management, will focus its investments on what it calls "bold technology entrepreneurs" worldwide, firms that have already