This will add your current IP address to the security group of choice. Assumes EC2 tools are on your PATH.

add-to-security-group

#!/bin/bash

# Initialize our own variables:
GROUP="default"
REGION="ap-northeast-1"


# Get our real public IP.
IP_ADDRESS=`curl ifconfig.me --silent`

while getopts "r:g:" opt; do
    case "$opt" in
    g)
        GROUP=$OPTARG
        ;;
    r)  REGION=$OPTARG
        ;;
    esac
done

echo "Adding access for ${IP_ADDRESS}/32 to all ports on ${GROUP}/${REGION}."

ec2-authorize ${GROUP} --region ${REGION} -s ${IP_ADDRESS}/32 -p -1