Rebundeling a running ec2 instance....

ec2-bundle-vol --prefix what_you_want_to_name_it -d /mnt/ami -c pathtocert.pem -k pathtokeyfile.pem -u 123456789 -s 10240 --kernel aki-9b00e5f2 -r i386

-d, --destination PATH
-c, --cert PATH
-k, --privatekey PATH
--kernel ID Id of the default kernel to launch the AMI with.
-r, --arch ARCHITECTURE Specify target architecture. One of ["i386", "x86_64"]
-s, --size MB The size, in MB (1024 * 1024 bytes), of the image file to create. The maximum size is 10240 MB.

(change the kernel type and arch to suite your needs... might as well use the largest size 10240)

This will bundle your running instance, and place the files in /mnt/ami

ec2-upload-bundle -b bucketname -m /mnt/ami/what_you_named_it.manifest.xml --access-key XYZ --secret-key XYZ

This will upload your bundled image to your bucket.

ec2-register /bucket/what_you_named_it.manifest.xml

The last step is to register your image, you will get back the AMI ID, and can either start your instance on the cmd line, or simply login to the web console and start it.