If it’s new, and U3 isn’t on it already, probably not. Easiest way to verify if it’s U3 compatible, download U3 and try to install it. If the device is not compatible you’ll get a message saying so.
Another option for securing the device is this: http://forums.sandisk.com/t5/Cruzer-flash-drives-Solid-State/SanDisk-SecureAccess-Password-and-encryption-software/td-p/217852
As for using it with PortableApps, sure.
