If you have the aws cli tool installed this will list all of your instances and their public IP addresses in all regions for you:

    for region in `aws ec2 describe-regions | awk '{print $NF}'`; do echo $region; aws ec2 describe-instances --region $region --query 'Reservations[].Instances[].[[Tags[?Key==`Name`]| [0].Value], PublicIpAddress]'; echo ; done