Joel Spolsky's answer here is an excellent primer on why companies have IP assignment clauses: http://answers.onstartups.com/questions/19422/if-im-working-at-a

Joel Spolsky's answer here is an excellent primer on why companies have IP assignment clauses: http://answers.onstartups.com/questions/19422/if-im-working-at-a-company-do-they-have-intellectual-property-rights-to-the-stu http://answers.onstartups.com/questions/19422/if-im-working-...