The phonebook has space for 1000 contacts and 7000 numbers. You can choose to view contacts in the phone memory or on SIM, but not both. Either way you can set up the phone to autosave to SIM all contacts that are being saved to the phone memory. You can also back up your contacts list on the memory card and restore it from there.
Editing a contact employs the tabbed interface used throughout the phone. There are five tabs that group related contact details. The first tab is for names and numbers, next up is web addresses such as e-mails and URLs. The third tab is for storing a picture, a custom ringtone, group, message tone and voice command, the fourth is for postal details and finally the fifth has fields for a note and a birthday (which you can add to the Calendar too).
The name of the contact is written in only one field, but you still have the option to order contacts by first or last name. The phone guesses which is which and it does it very well. Naturally, you can search by gradual typing.
Handling of calls is excellent and we didn't experience any voice quality or reception problems with the Sony Ericsson C903. Call clarity is great in both the earpiece and speakerphone.
Smart dialing or Smart Search as Sony Ericsson are calling it is a great boost to usability. It looks up contacts whose numbers contain the digits you have typed or whose names begin with the corresponding letters.
The tabbed Call Log application should be familiar if you've used a fairly recent Sony Ericsson handset. It displays in four tabs, including All, Answered (Received), Dialed and Missed. When there are several calls made to or from a single contact, only the last one gets displayed.
We were unable to perform our standard loudspeaker performance test, as the pre-release unit we had performed inconsistently. We will update this review as soon as we get our hands on a final unit. This also concerns the audio quality test.
Messaging is probably the only place where the interface has seen changes. The new thingy is the alternative conversation-style layout, which displays message threads - the SMS communication with a certain contact is organized as blobs in an instant messenger.
Switching between the conversation-style layout and the regular Inbox is only a matter of toggling a tab.
Another interesting fact is that if you get a reply while you're still in the thread, it will be automatically added to the conversation, instead of appearing as an alert on the home screen.
Along with the standard messaging functionality, Sony Ericsson C903 offers the proprietary Manage Messages feature, plenty of settings for accounts, and the option to assign categories to messages. The Manage Messages application enhances message handling. Messages can be moved to memory card or phone memory, arranged by categories, date, size, and contact. Categories also allows quick and comfortable sorting of messages with separate folders.
Sony Ericsson C903 handles all common types of messages, all of which - save for emails - share a common inbox. When composing a message, a warning is displayed when you exceed the 160-character limit, to let you know that the message will be divided in two (or more if necessary) parts for sending.
There is also a rich T9 dictionary. The SMS and MMS messages share an editor; when typing SMS you can easily convert it into an MMS via the options menu or using the attach-stuff toolbar below the text box to insert images, animations, videos or sounds.
The phone automatically downloaded the settings for our Gmail account. The options to view messages full screen and change font size really helped to get a lot of text on the screen. Even at the smallest font setting text remained legible.
For email you get the Manage Email feature, which has the same functionality as the one for text messages. Saving attachments is problem-free, even if the phone doesn't recognize the file type.
The phone can't handle any documents that are attached to emails (such as .xls, .doc, or .pdf files for example) due to the lack of a document reader.