finding nat'd IP address?

[Chandhee Thala]

if i connect to the net with a cable modem or some other device that uses
NAT and gives me a private IP addresses, what is the most "Elegant" way to
get my real IP? (assume that the device itself will not let me have it).

I can go to some site that gives the visitor their ip address and screen
scrape, but I'd like to know if there is a cleaner solution before I start
scripting.

thanks
c