Congratulations to Cicadaman & co. for getting Froyo running on the Nook Color! Visit the nook Color portal!
See Rooting new hardware FIRST if you have a nook original with a 1003* serial# or above.
Talk:Nookie FroYo: Burning a bootable SD card
From nookDevs
Instructions worked faultlessly. Using for several days now and added numerous apps and settings. Had installed on 4GB class 4, and very satisfied, but have ordered an 8 GB class 6. Is there a simple way to transfer the entire existing image, including all apps, from the 4GB to the new 6GB micro sd card?