Rounding out the phone's exterior are the headset and charger jack on the right spine, and the voice recorder, volume rocker, and voice command key on the left (the voice command key doubles as the speakerphone key). The volume and voice controls felt flush against the surface of the phone and were a little tricky to press.
As we mentioned, the Sanyo S1 is pretty light on features, so let's get right to it. The Sanyo S1 comes with a dinky 200-entry phonebook with room in each entry for six numbers, e-mail and Web addresses, a home address, and a memo. You can also assign the number to groups, plus one of 16 polyphonic ringtones. Other features include text and multimedia messaging, instant messaging, a vibrate mode, a speakerphone, voice command, a voice recorder, a calendar, an alarm clock, a calculator, a stopwatch, and a world clock. On the higher end, there's e-mail, a wireless Web browser with access to Sprint Vision, plus Bluetooth. You can use the Bluetooth to connect to headsets, of course, but the S1 also supports modem connect via Bluetooth. This means that using Bluetooth, you can tether your laptop to the S1 for on-the-go surfing. The S1 also has a lock code for parental control.
Personalization options are fairly standard with the Sanyo S1. You can customize it with wallpapers, screensavers, different clock styles and greetings, and alert tones. Since the S1 comes with a browser, you can download more from the Sprint Vision network. There's only one game included--NFL Mobile--but you can always download more.
We tested the Sanyo S1 in San Francisco using the Sprint network. Call quality was mediocre, with callers reporting quite a bit of noise and echo in the background, and not hearing us very well at times. On our end, we heard them just fine, though we did get a few static problems, as well. Speakerphone didn't do much better. Volume was loud enough, but callers had to keep on asking us to speak up. Using a Bluetooth headset improved the call quality a little bit, but not by much. We paired the Sanyo S1 with the Plantronics Voyager 520 without a problem.
The Sanyo S1 has a rated battery life of 3.5 hours. Our tests revealed a talk time of 3 hours, 45 minutes. According to the FCC radiation tests, the SAR rating of the Sanyo S1 is 1.48 watts per kilogram.