How is Espionage different from Disk Utility's encrypted disk images?

It's important to note that Espionage uses the same encrypted disk images that Disk Utility can create.

That said, the similarities stop there.

By merging the disk image and the mount point together into a "folder", Espionage not only allows you to do things that are not possible with disk images (like encrypting your email), but it makes the task of securing your data painless and simple.