fanoush's shell script works like a charm on my N800 with OS 2008 together with my HTC smartphone.

But to make Nokia's applications aware of the internet connection, you need to set up a DUMMY connection.
Go to Connection Settings, add a new WiFi connection, and name it DUMMY. Then in the terminal do the following:

gconftool-2 -s -t string /system/osso/connectivity/IAP/DUMMY/type DUMMY

Now connect to the DUMMY connection and then run fanoush's script.