In Nortel's recent bankrupcy, the liquidation of the IP assets led to a bidding war. Google offered $900M for the patents; Apple and Microsoft created an alliance (with RIM, Sony, EMC, Ericsson) to offer $4.5B for the same patents^. Certainly there was a great disparity in these bid prices. How can you objectively determine the value of a portfolio and patent duration. Let the tools at IPstreet.com help you.
There are three types of different patents (1) Utility Patents: Issued for the invention of a new and useful process, machine, manufacture, or composition of matter, or a new and useful improvement thereof, it generally permits its owner to exclude others from making, using, or selling the invention for a period of up to twenty years from the date of patent application filing ++, subject to the payment of maintenance fees. Approximately 90% of the patent documents issued by the USPTO in recent years have been utility patents, also referred to as "patents for invention." (2) Design Patents: Issued for a new, original, and ornamental design for an article of manufacture, it permits its owner to exclude others from making, using, or selling the design for a period of fourteen years from the date of patent grant. Design patents are not subject to the payment of maintenance fees. (3). Plant Patents: Issued for a new and distinct, invented or discovered asexually reproduced plant including cultivated sports, mutants, hybrids, and newly found seedlings, other than a tuber propagated plant or a plant found in an uncultivated state, it permits its owner to exclude others from making, using, or selling the plant for a period of up to twenty years from the date of patent application filing. Plant patents are not subject to the payment of maintenance fees.
In celebration of Noah Webster's Birthday (October 16, 2009), we have prepared an updated website. 
