Many users who want to put their webcam on the Internet do not have a permanent IP address. Dynamic DNS services allow you to publish a fixed address without having to worry that your IP address may change.
Two such services are:
http://www.dns2go.com $19.95/Year
With these services you will enable you to use an address like http://bdlhome.dyndns.org rather than having to know/remember your ISP assigned external IP address.