David S. Isenberg:

"I'm talking about a telephony program that runs in a vanilla Compaq Ipaq palm-sized device with a vanilla 802.11b wireless connection to the vanilla, unmanaged, public Internet. It uses plain old headphones and the Ipaq's on-board microphone. It runs with Microsoft's Pocket PC operating system. [...] In the test call I made from Atlanta to another device running the software in San Francisco (about a dozen router hops), the voice of the fellow at the other end was crystal clear. There were no echoes and no audible glitches. The delay was just noticeable to my fairly experienced ears. This delay -- unlike other software-only Internet telephony I've tried -- was not enough to interfere with the dynamics of the conversation."