The KX440 is a utilitarian-looking phone with far more of an accent towards functionality than having particularly flashy design features; this is a working phone that more or less climbs up on the rooftop and screams "I'm a working phone" at the top of its lungs, eschewing glow-in-the-dark snap-on covers, silly ring tones or faux leopard skin cases. Instead, what you get is a rugged looking phone that's particularly easy to hold in the hand, thanks to the side rubber grips. Weighing in at 122g and with dimensions of 114 mm x 49.2 mm x 27.8 mm, it's a moderately large phone by modern standards, and that's largely to do with the inclusion of a largish battery and particularly a large speaker to help implement the phone's push-to-talk capabilities.
The front face of the phone incorporates standard dialling buttons, a concave five-way directional button and standard calling buttons. On the left hand side of the phone you'll find a big red history erasing button, perfect for blanking out the last five minutes of existence. OK, you won't -- we're just checking to make sure you're paying attention. The big red button on the side implements the phone's push-to-talk functions, and is held down during calls in exactly the same way that you'd use a walkie talkie.
While the KX440 is a mobile phone, and can thus handle phone contacts, normal mobile calls and predictive text SMS, it's clear that absolutely nobody's going to buy one based on those specifications. What marks the KX440 out from the pack is the inclusion of push-to-talk capabilities. Push-to-talk isn't a feature that everybody needs -- and arguably, it's quite a niche application, as the high per-second cost and the inherent limitations of push-to-talk make it a best-case solution only where you're likely to be using actual walkie-talkies anyway. In its favour, the KX440 has been built with exactly these kinds of largely industrial applications in mind, and so the main functions are easy to implement and rely on very simple menu structures with a minimal amount of flash.
We tested a pair of KX440 mobiles using Telstra's push-to-talk service, which will currently cost you 1c/second for mobile-to-mobile calls (2c/second for group calls, with monthly unlimited packages also available). In theory, you could just about manage a quick call for less than the price of a standard SMS -- as long as you didn't get chatty, that is.
There are some limitations with PTT technology that have to be borne in mind, however. For a start, it's quite intrusive, as unless you change the on-phone options, you'll cut through with voice the moment you hit the PTT button with a suitable contact selected. It's a great way to get people staring at you on a train, for a start, as the integrated speaker is very loud. The other major limitation (aside from remembering not to hit the button while someone else is talking) is that there's a noticeable gap between sending and receiving messages, which makes calls that bit longer to conclude. If you're a frequent mobile chatterer, you'll find it a bit tiresome to communicate in this staccato-like fashion.
Like the rest of the phone, the battery on the KX440 is rugged and lasts for a solid length of time. In our testing we managed four days of quite heavy usage of the phone, using both PTT and regular phone capabilities.