[Please Note: This story was written back in 2008]
Nokia Europe has released software version 4.0812.4.x for the N73
(see *UPDATE below).
This software version includes support for mobile TV (when used with SU-33W receiver) and Express Mail clients. This release also includes updates and improvements to Nokia Maps and improved Java support.The phone can be updated via the Nokia Software Updater (only Windows I’m afraid) which can be downloaded here.
Run the update afterwards and hey presto you should be running the latest OS, hopefully!.