Finding External IP Address for home when away from home.

I have two cameras in my home that I wish to access when I am away from home.  I know with dynamic ip addresses that the external ip address will change.  I wish to access these cameras through single port forwarding in my router but I need to know the external ip address for my home.  I used to access them with an ip address such as 68.1.1.1:8095.  How do I find the 68.1.1.1?  Thanks.