I was looking for something like Steganos LockNote:
https://www.steganos.com/us/products/home-office/locknote/overview/but not to store text only but to store files instead. When you close it it encrypts itself back.
Imagine LockNote with ability to contain files and folders instead plain text. AES 256 is somehow obvious.
I'm looking for such tool for my USB drive. I tried TrueCrypt but it's just too crappy to use with PortableApps menu. LockNote on the other hand works great.
I already gave this idea to Steganos developers but they don't seem to be much interested in it.
"Comodo PortableVault" anyone?