The smartphone war between the iPhone and Android has now extended from the sales floor to the courtroom.

Let's start with the sales news.  According to research released Monday by tech research firm Canalys, handsets based on Google's open source Android operating system accounted for a whopping 44% of all smartphone shipments in the United States in the third quarter of 2010.  Apple's iPhone finished a distant second, accounting for 26% of all US handset shipments.

Of course, the iPhone was still by far the single most popular individual device on the market, as Android's market share was split between popular devices such as the Motorola's Droid X and Droid 2, as well as HTC's Evo 4G.  But Android's emergence in the smartphone market is simply too impressive to be ignored, as worldwide shipments of Android devices have grown from 1.4 million in Q3 2009 to over 20 million in Q3 2010, or a growth rate of roughly 1309% over the span of a year.

iPhone and Android war extends from sales floor to courtroomOne advantage that Android has over its operating system competitors at Apple and Research in Motion is that multiple device manufacturers can use it for free as a basis for smartphones.  Thus, you have HTC, Motorola and Samsung all competing to see who can make the most popular and successful Android devices while Apple only releases one new version of the iPhone per year.

But as mentioned earlier, the battle between Apple and Android devices has now entered the legal realm as well as the commercial realm as both Apple and Motorola have filed patent lawsuits against one another. Last month Motorola sued to have 12 of Apple's patent invalidated on the grounds that Apple was wrongfully using the patents to target Android-based devices.  HTC, which also makes popular Android devices such as the Droid Incredible and the Evo 4G, has also sued Apple to challenge the validity of some of the patents being challenged by Motorola.

Apple fired back at Motorola today by alleging that Motorola's Android-based devices are infringing on six patents, none of which are the same patents that Motorola is trying to invalidate.  The two big patents in the suit involve multi-touch smartphone technology like that used in the iPhone and in Android devices.  According to Patently Apple, several Motorola devices are alleged to infringe on Apple's multi-touchscreen patents, including the Motorla Droid, the Droid X, the Cliq and the Backflip, all of which use Android as their operating system.

Apple CEO Steve Jobs also recently injected himself into the iPhone-Android feud by criticising Android for being a fragmented platform that worked differently on multiple different device types.  He said that this made things difficult for app developers who had no idea whether their application would behave differently on devices that have varying screen sizes.