structuralaggie,
I guess the points that I am really trying to make are:
1) The Banjo developers are taking an easy route by binding the license with a specific CPU (it's either hard or impossible to spoof the internal CPU serial number). Unless you have a laptop or a second copy of Banjo, you don't always have the ability to sign your documents using Banjo. Using a hardware lock or electronic license server should be a good compromise between ensuring piracy protection and flexibility of use.
2) Your private key data reside on the computer's hard drive (I would personally make a backup copy stored on some durable and secured media). This is really a personal key, and there may be situations where you don't want personal data residing on a device that is owned by your employer. At any rate, you should be able to permanently delete this information from the computer's drive. Your PE license is issued to you - you just indefinitely "rent" it to your employer in exchange for certain compensations.
3) What happens in the instance where there are multiple professionals signing documents (not necessarily the same documents)? Does the firm buy them each a copy of Banjo? I would imagine that it depends on the size of the firm, but it is not hard to imagine smaller firms installing one copy on the computer normally used by an adminisrtative assistant and having him or her "sign" all the electronic reports or drawings on behalf of the PEs.
I like some of the features of Banjo, but feel that the implementation of some of the licensing and key management could stand some improvement. Again, maybe I'm too paranoid.
IFRs,
FYI, Adobe 7.0 includes support for 3rd-party authenticated timestamps to be included in the digital signature.
Jeff