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.
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.