The major phone makers -- including Apple, Nokia, Microsoft, Motorola and Taiwan's HTC -- are increasingly turning to patent litigation as they jockey for any edge to expand their share of the rapidly growing smartphone market. Companies such as Nokia are also seeking to protect their business as the popular iPhone encroaches on the rest of the industry.

The lawsuits cover all aspects of basic phone use, from technology used to synchronize email, calendars and contacts, to methods to extend battery life.

ENTER EDIG...post Markman.