If you own a Nook Tablet and want to dual-boot the device's integrated operating system (Gingerbread) alongside a full-blown version of Jelly Bean, well, you might want to check out N2Acards, formally known as Nook2Android.
The software magic that's key to allowing the dual-boot functionality is thanks to Cyanogenmod. The memory card is slated to be offered in 8 GB, 16 GB, 32 GB, and 64 GB versions. Pricing will vary depending on capacity between $30 and $90.
Of course, if you don't need an extra memory card you can just download the OS image for $20, load it onto your existing memory card and start using Android 4.1 right away.
Now it should definitely be noted that the software sold by N2A is actually available online for free, although some might find N2A's fee worth the convenience of simply buying a card with the OS preinstalled or downloading a pre-configured version.
However, I suspect that more than a few people will be bothered by the fact that N2Acards is making money off software they didn't develop - which was actually coded by the hard working folks over at XDA Developers.