(This might not be an Ubuntu-specific question?)
When I installed 9.10, I opted to encrypt my home folder using ecryptfs, but then I discovered this locked me out of my ext3 partition when I tried to access it from Windows on my dual-boot machine (using some free ext2/3 driver that I got somewhere, not even sure which one).
Is there a way to mount an encrypted home folder in Windows?
Unfortunately, it looks like no Windows support for ecryptfs is planned: Is there a windows port of this available or in the works?
If you use something like TrueCrypt you can access your drives from both Windows and Linux as long as you know the password. If you formatted it as ext2/3 you will need a ext2/3 driver to access it from Windows.