I make some test to install the google calendar on my Nook Touch.
First follow the instruction to install the Market.
Then download the 2 apk files on this post
Then install the 2 files on your Nook Touch with that command:
adb shell mount -o rw,remount -t ext2 /dev/block/mmcblk0p5 /system
adb push Calendar.apk /system/app
adb push CalendarProvider.apk /system/app
chmod 775 /system/app/Calendar.apk
chmod 775 /system/app/CalendarProvider.apk
It works for me but there is some problems:
1) a big picture of the SD-card on top of the screen
2) some text are not visible on settings
3) sync works from google server to nook