Review: Sony Ericsson W580i
Even without a send and end key, calling works just about as you'd expect it to. From the home screen, the left soft key, which works as the send key when calling, brings up the recent call list. In calls the right soft key becomes the End key, which is the only place that Sony Ericsson violates its consistent navigation, but at least it's done for a good reason.
You can also use the slide to answer and end calls, but each action is turned on and off separately in the settings. Oddly, open to answer is on by default, but close to hang up is not. The first few times we shut the phone to end a call, the other party heard us talking until they hung up, which could have been quite embarrassing.
Opening the contacts application displays your contact list, which you can jump through by triple tapping the name you're looking for. When a contact is selected, you can scroll left or right to switch through his various numbers and email addresses.
Pressing the left soft key with a number selected dials that number. Unfortunately the back key is part of the same circular button as the left soft key. So if you just mash down on that button, you could hit back instead of call. This will exit the contacts application and force you to repeat your search all over again. I did this far too many times and found it quite frustrating. Separating the back key would solved this without needing to add send and end keys.
Contacts can hold multiple phone numbers and email addresses per contact, as well as 2 street addresses, a web address, a birthday and notes. You can select a picture, ringtone, and even a light pattern for any caller.