In any case your IP is masqueraded with some other ip so ifconfig wont help. So go to http://checkip.dyndns.org/, it will display your public ip. Now you may be able to access your machine from any where in the world.
alas, behind NAT :-(
BTW your solution gave me an idea to check if i am connected :
if wget -q -O /tmp/index checkip.dyndns.org then echo "Connected :-) " else echo "Not connected :-( "
Regards, Nikhil