Guys,
I am sitting here in Chiangmai and just tested it without any problem for my Nuvi (Garmin Updater version 2.42 I think - see the screen grabs). Yes, some websites are off-limits but not the Garmin site. Actually, you can download tons of Garmin maps including the latest (2010) maps for the USA, Australia, New Zealand, Europe, Vietnam, Laos, Cambodia, Thailand, S.E. Asia, Malaysia, Singapore, etc. You have to search for them though and may have to register before you can download the maps. Just downloaded the Vietnam GPS map.
Download Webupdater and install it on your PC. Either at the end of the Installation process or once when it is installed start the programe.
You will then get a screen where its asks where your GPS is located.
It will then check if there are any updates for your GPS, etc. When the firmware is updated, check again as there may also be an update for the GPS chip in your GPS.
Once everything has been checked you will see this:
Quite simple and straightforward.
Mind you, I know from people at forums that they sometimes have lots of problems downloading the latest firmware using the Webupdater. Trying again and again in almost all cases will work.
Make sure that the batteries in you GPS are fully loaded. In case your batteries give up during the upload process you have a very good chance that you will have to send it to Garmin to get things fixed and, as it is your fault, it will cost big bucks.