Take a look here:
You will find some interesting informations about reading/writing an image and opening then back of your glo.
I use a 16GB SD-Card since 11-25-2012 following this thread without having any trouble till now.
Plus having a safe backup. I was downloading the wrong 2.3.2 firmware (Touch) and bricked my glo. Putting back the Backup and write my 16 GB Card again.