For smartphone users, Jabra has also partnered with a few third-party developers so you can use certain voice apps with the Stone 2. That includes Vlingo, Dial2Do, and Voice Assist. The Jabra Stone 2 comes with an on-package redemption code that will let you download up to three free apps. You can find out which voice-enabled apps are optimized to use with the Jabra Stone 2 on the Jabra Web site.
We paired the Jabra Stone 2 with the Apple iPhone 4, and we did so without the need for a PIN code, though this may depend on your phone. Incoming call quality was pretty good--callers sounded natural with plenty of volume, though we did hear the occasional static and hiss. The quality was not that much different without the headset.
As for outgoing calls, the quality was not quite as good. It does do a decent job of blocking out extraneous noise thanks to Jabra's Noise Blackout technology--we tested it in a busy cafe during lunch hour, and our callers could still hear our voice above the din in the background. However, our voice sounded oddly digitized and harsh, and callers frequently said they detected a lot of digital chatter--beeps and clicks--when we spoke. We shut off the headset and switched back to the phone to see if the quality improved, and callers said the digital chatter went away when we did.
The Jabra Stone 2 has a rated talk time of 2 hours with the headset alone, with an additional 8 hours if combined with the portable charger.