Turn on/off the "click" sound made by the camera by selecting the 'Silent' profile or by turning warning tones on/off:
Menu > Profiles > "select your activated profile" > Personalise > Warning tones > On/Off.
(This also effects the sound of Java games and apps).

To change background image go to:
Menu > Tools > Settings > Phone > Standby mode > Background image > Yes > "choose an image".
The best size for background images is 174x132 pixels.

Display an image when someone's calling:
Menu > Contacts > "select a contact card" > Options > Edit > Options > Add thumbnail > "choose an image".

Add a personal ringing tone to a contact:
Menu
> Contacts > "select a contact card" > Options > Open >
Options > Ringing tone > "choose a ringing tone".

Delete all messages from your Inbox at once:
Menu > Messaging > Inbox > Options > Mark/Unmark > Mark all > Options > Delete.

Send or hide your caller ID: Go to: Menu > Tools > Settings > Call > Send My
Caller ID > 'Yes', 'No' or 'Set By Network' to follow the default settings of your home network.