If you're on Sprint, and want the stock ROM, and you're running Windows XP, then look here:
http://forum.ppcgeeks.com/showthread.php?t=16806
If you're on Sprint, and want the stock ROM, and you're running Windows Vista, then look here:
http://forum.ppcgeeks.com/showthread.php?t=16886
If want dcd's custom Titan ROM, or if you're on Verizon, Alltel, or Telus, then look here:
http://forum.xda-developers.com/showthread.php?t=362566
NOTE: After the update some are experiencing loss of phone functions (dial in-out). To recover from this, before updating, make sure you record your MDN and MSID. First go to your dialer and dial ##MSL# (where MSL is your unique MSL code for your phone). The MSL unlock code is used for programming your phone yourself, and is unique for every phone. You can retrieve the MSL for your phone by using the
GetSPC application. It's essentially a keygen that calculates what the MSL should be from the hexadecimal ESN (case-sensitive). You can get your hexadecimal ESN from several places including the back of your device if you remove the battery. You can download GetSPC from
HERE. Otherwise you can call Sprint technical support, tell them you're a developer, and you need the MSL number for your phone. The MDN should be your phone number. Finally, go to your dialer again, and dial
##3282#, your MSL is the unlock code, then make sure you record the settings there. The important things are your username and AAA password (HA password should be 'secret').