http://blog.pmarca.com/2007/06/the_pmarca_guid_1.html http://blog.pmarca.com/2007/06/the_pmarca_guid_2.html http://blog.pmarca.com/2007/06/the_pmarca_guid_3.html http://blog.pmarca.com/2007/06/the_pmarca_guid_4.html http://blog.pmarca.com/2007/06/the_pmarca_guid_5.html