Google and Apple have partnered on a bid of more than $500 million to buy the bankrupt Eastman Kodak's digital patents, a not-uncommon practice among rivals who want to prevent litigation. "They have decided to come together in this process to reduce the cost of purchasing the Kodak patents, while meeting their business needs," said Richard Ehrlickman, president of IP Offerings, a patent brokerage and consulting firm. In other patent news, the U.S. Patent Office has issued a preliminary ruling invalidating all of Apple's 20 claims to a group of multitouch patents.