Admob is out with its latest roundup of traffic metrics on the wireless web (PDF), and although the iPhone still rules, Android is gaining significant ground. The iPhone accounted for 40 percent of wireless web usage in August, up from 33 percent in February, but Android more than tripled its share of traffic, jumping from 2 percent to 7 percent over the past six months. The really notable thing about Android's performance is that numerous upcoming handsets based on the open source OS haven't even arrived yet, including ones from LG, Motorola, Samsung, and INQ. Check out more in GigaOm's story.