UNLOCKING

Most non-BB5 Nokia handsets can be freely unlocked.  There is a free unlock calculator available on the extras page of the site, but please bear in mind that you only get five attempts to unlock the handset via code - after that you'll need to use a cabled solution.

CODES

These are generic codes that work on most Nokia handsets:-

Show IMEI - *#06#
Show Firmware Version - *#0000#
Warranty Menu - *#92702689#
Activate EFR - *3370#
Deactivate EFR - #3370#
Activate HFR - *4720#
Deactivate HFR - #4720#
Display SIM Clock Status - *#746025625#
Reset Timers & Game Scores - *#73#
Production Serial Number - *#7760#
Own Number (Vodafone only) - *#100#
Format Phone (Symbian) - *#7370#

CUSTOMISING

The obvious choice for customising Nokia phones is the Nokia written PC-Suite.  PC-Suite has the major advantage of being freely distributed, but it doesn't work with all handsets and is weak in certain areas. 
First of all you need to decide how you intend to connect your handset to your computer.  On many phones you'll have the choice of cable, infra red or BlueTooth connectivity, but on some of the lower handsets you'll not officially have any of these options (e.g. the Nokia 3310 never officially had any connectivity options from Nokia, but third part cables and applications are available). 
If you have the option of Infra red or BlueTooth, I'd strongly suggest taking one of these routes rather than the cable.  Whilst the cable will be faster (and probably more reliable) you'll find that Nokia very quickly change the connectivity options for their phones so you will more than likely end up purchasing a new cable each time you change your phone.  At least with Infra red or BlueTooth they are recognised and supported standards that are common to many manufacturers.  If you still decide you prefer a cabled solution, you should be aware that many third party (copied or cloned) cables based on the Prolific chipset will not function with PC-Suite, so check with your supplier before buying.

The obvious competition to PC-Suite comes primarily from two suppliers - Mike Bradley and Oxygen.  I'm not going to attempt to tell you which is the better product as both have their uses and advantages.  Oxygen is the more versatile product, but is not particularly user friendly and the licensing is quite restrictive.  Mike Bradley has taken a different approach and has concentrated on providing separate products for different applications.

Mike Bradley - There are now four products in the range. 

    Logomanager was (and still is) one of the best applications for customising Logos, ringtones, start-up animations and a few other bits and pieces.  Unfortunately Logomanager is of little use for newer handsets and so is only really to be considered if you have a mono screened Nokia.

    MobiMB is designed to allow you to browse the contents of your phone almost as though they were a drive on your computer.  It allows you to transfer (to and from the phone) logos, wallpaper, ringtones, games, applications and basically any user content available on the phone.  I'm not going to attempt a full review here, but it does work extremely well whilst being limited in application (phonebook & SMS management etc.).

    Mobius/PX is basically a phonebook & SMS management utility.  It's the perfect compliment to MobiMB and combined with that will give most people the functionality they need to manage their phone.

    Polyphonix Studio is a fully featured MIDI/SP-MIDI editor.  If you're serious about creating and editing your own polyphonic (MIDI) ringtones it would appear to be the ideal application.

Oxygen - Oxygen offer a few different products, but the main one of interest to most users is Oxygen Phone Manager.

    Oxygen Phone Manager II - This software supports most phones in the current Nokia range (Symbian excepted).  There really isn't much that Oxygen won't do - phone book & SMS synchronisation, upload (and download) of content, ringtone editing facilities etc.  The interface is (in my opinion) cluttered and the licensing is overly restrictive in that it will only function with the registered handset for a period of one year.  If you change your phone inside the one year support period Oxygen will generate the required unlock code to use the software, but outside that period you'll find yourself paying them to do it or for any upgrades to the software.  There's no denying that it is the most fully featured customisation package, but you'll have to decide if the restrictions are severe enough to prevent you purchasing it.

    Oxygen Phone Manager For Symbian - This provides much of the functionality of the above software but for Symbian based handsets (and not just Nokia's anymore).