After several years of waiting, Amazon now has new feature to tag instances, volumes, and other resources. Need to check it out? Amazon EC2 Resource Tagging

Simple test with Tagging an EC2 instance and an EBS volume.

1. Download the latest API tools here

2. In your terminal update the variable EC2_HOME and PATH:

 shell_prompt$ export EC2_HOME=/Applications/ec2/ec2-api-tools-1.3-57419
 shell_prompt$ export PATH=$EC2_HOME/bin:$PATH
 shell_prompt$ ec2_version 
 1.3-57419 2010-08-31

3. Now for the tagging(just replace the instance-id and volume-id):

shell_prompt$ ec2-create-tags i-12345678 vol-12345678 -t webserver=host2
TAG	instance	 i-12345678	webserver	host2
TAG	volume	vol-12345678	webserver	host2

shell_prompt$ ec2-describe-tags
TAG	volume	vol-12345678	webserver	host2
TAG	instance	 i-12345678	webserver	host2

I’m now looking for a way to tag my current instances probably by writing a script.
Happy tagging.