USEFUL SYMBIAN PHONE TIPS.

• Tip 1 : Do u know how to use the edit button pencil button)? Heres how... in the inbox for example; if you want to delete multiple sms, simply hold the edit button, scroll down,and then press `C` to delete the marked sms.
  The edit button can also be used to copy and paste text in sms, simply hold it and scroll across, choose copy.
• Tip 2 : Shit happens,on a smartphone,its inevitable to do something wrong,and this calls for a format of phone.
  To format your phone,press *#7370#, then enter the lock code,which is the sec code of the fone.

  NOTE : Your battery must be full, else if format is disrupted by low battery,the consequences will be disatrous.I heard the code *#7780# works too, pretty much the same i tink. for 6600 users, to format your phone,there's an alternative way.

  Press and hold <3>, <*>,and the green button,then power on phone,keep holding the 3 buttons, till you come to a format screen.
  This method ONLY works on 6600, and need not enter the sec code.
  The default code is 12345.
• Tip 3 : TO NGAGE USERS; Do u know u can install .sis files simply using the cable given?
  Just plug it in, place the .sis file anywhere on e:(i.e mmc), not in any folder,but root of e:, disconnect, then look for it in manager to install.
• 
  Tip 4: Save your battery life and system memory by regulary checking the task manager which can be accessed by holding down the menu button.
• 
  Tip 5: Type *#06# to display your IMEI serial number, very valuable for unlocking your phone to use other sim cards...
• Tip 6: Save memory when installing apps, by installing over bluetooth. This can be done using the nokia phone suite and a bluetooth serial connection.
  Only works with.SIS files, so java still has to be sent to the phone, but will save space when using .SIS files.
• Tip 7: Do you know you can change the operator logo?
  Simply use a file manager like FExplorer or SeleQ to add the folders:"c: -system/Apps/phone/oplogo". Add a .bmp picture to folder "oplogo" and restart your phone! The .bmp picture size needs to be: 97 x 25 pixels.
• Tip 8:
  First, you need to know what Bluetooth is. There are lots of types of modern devices that incorporate Bluetooth as one of their many features. PDAs, mobile phones and laptops area few of these modern devices.
  This means that Bluetooth enabled devices can send things like phonebook/address book contacts, pictures,files & notes to other Bluetooth enabled devices wirelessly over a range of about 10 metres.
  Now, using a phone with Bluetooth, you can create a phonebook contact and write a message, eg. 'Hello, you've been bluejacked', in the 'Name' field. Then you can search for other phones with Bluetooth and send that phonebook contact to them.
  On their phone, a message will popup saying "'Hello, you've been bluejacked' has just been received by Bluetooth" or something along those lines.
  For most 'victims' they will have no idea as to how the message appeared on their phone.
• 
  Tip 9: While you are viewing a picture in your phone's gallery, press one of these shortcut keys.
  1 - turn image anti-clockwise
  3 - turn image clockwise
  * - toggle on/off of full screen
  5 - zoom in
  0 - zoom out
  7 - view full screen.
• Tip 10: Check if the recepients phone is on Delivery reports or Type '*0# your message' in the message composer windowspace then write your message, the recipient will not see the star zero hash but - just the message.
  When they read it will relay a message back to your phone showing the time they recieved it. (haven't tried it myself though).

I guess this was helpful.
If you have more,please share with us.