The mobile version is explained more here from Google. It requires downloading Java-based software which works with many mobile phones but certainly not all of them. Count me among the ones out of luck. It also won't work on Palm devices nor, from what I can tell, Windows Mobile/Pocket PCs. The FAQ explains more. All supported devices are here.
Google's also made a new version of its personalized home page for mobile devices, using this tool. Google Personalized Homepage on Mobile Phones from Google Blogoscoped and Google Beefs Up Mobile Home Page from Micro Persuasion cover more on how this works.
Very oddly, regular Google Maps hasn't gained either traffic information or pedestrian directions. That's too bad, because if they did, I could use the regular browser on my phone to get this type of information. Since Google fails to do this, here are alternatives from its competitors.
Yahoo rolled out real-time traffic information into Yahoo Maps well over a year ago. Our SearchDay article Yahoo Offers Real-Time Traffic Reports covers more about this, and help info from Yahoo is here.
Meanwhile, Windows Live Local from Microsoft added real-time traffic info about two months ago, as our past blog post Windows Live Local Adds Traffic and Sharing covers. Help info from Microsoft is here.
Ask Maps doesn't have traffic info but it does provide an option to get directions both for those driving and for walking, something Google only gives you on your phone.
Nobody walks in LA -- or The OC -- for that matter. But if Ryan on The OC really was trying to walk between locations as the TV series would make you think (see my personal blog for more), here's a rough idea of how the three hour trip by foot gets turned into only minutes through the miracle of television. Oh -- and it also demonstrates how walking directions work on Ask.
And speaking of my personal blog, I couldn't resist doing a quick post about my new favorite way of getting traffic information, via my watch. See Real-Time Traffic Via My MSN Direct Spot Watch for more on that.
Postscript: Gary Price has listed some additional real time traffic resources here