The Nokia Blog reports that the Nokia N73 Internet Edition Firmware 3.0638.0.0.43 update is now available. The Nokia N73 Internet Edition was only announced in Taiwan and Hong Kong, along with other Nseries Internet editions, but anyone with the N73 can change their firmware.
As with the earlier N73 Music edition, update is quite simple. All you need to do is change your N73’s product code to to 0539366 (Hong Kong’s language pack: English, Traditional Chinese, Simplified Chinese) or 0539364 (Taiwan’s language pack: English + Traditional Chinese) and mark the case “Enable”. Full details are available from here.
Again, be aware that this procedure will invalidate any warranty on your handset.