I recently got a new draft-N router(D-Link DIR655), to replace my old Linksys Wireless B router. Its working great, I have been running speed tests under many different conditions. I've been using speedtest.net for my iMac and the speedtest.net app on my iPhone. On my hardwired iMac, I hit around 15-16Mbits with both my old router and the new one, which is expected. I unplugged the ethernet cable and turned airport on, and I hit the same speeds through airport(~16Mbits). On my iPhone, however, I am only hitting speeds of around 4Mbits. I have not tried any other iPhones on my network. I don't see what could be holding back the speed on my iPhone but not my iMac. I could be wrong. I have gotten upto 16Mbits on my iPhone on other networks.