Google announced a brand new spider they are adding to the Googlebot line up - this bot is for smartphone related content and is named "Smartphone Googlebot-Mobile."
This new crawler was introduced because of the huge spike in smartphone based content. Google said "Googlebot-Mobile now crawls with a smartphone user-agent," to help increase Google's "coverage of smartphone content and to provide a better search experience for smartphone users."
The new bot goes by the useragent:
Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8B117 Safari/6531.22.7 (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)
The standard feature phone useragent remains:
SAMSUNG-SGH-E250/1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 UP.Browser/220.127.116.11.c.1.101 (GUI) MMP/2.0 (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)
DoCoMo/2.0 N905i(c100;TB;W24H16) (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)
We have seen signs of Google testing smartphone Googlebots in the past, but now it is official.
Skip Redirect for Smartphone-Optimized Pages:
Google has also introduced "Skip Redirect for Smartphone-Optimized Pages" to make the process of being redirected from a non-smartphone optimized page to a smartphone optimized page faster. In short, Google will figure out the URL for the smartphone page and send you directly there, instead of taking you to the first URL and then making the server redirect you. Google said it should save the searcher about " 0.5-1 seconds on average."
That being said, I am still a strong believer that for large content sites, you should have a single URL for each piece of content. Like we do on this site, so that people do not link to the www. version and the m. version of your site.
For more on that, see my latest mobile SEO story.
Forum discussion at WebmasterWorld.