SPKI Certs Usage

[Jay Listo]

I've been wondering about the feasibility of using SPKI certs.  I quite 
like some of the features (delegation) and relative ease of 
implementation (compared to X.509 certs)...of course, readability of 
certs could go a long way to helping end-users evaluate for themselves 
the trustworthiness of the cert. 

While pgp certs could probably be a good alternative (given the existing 
user base and infrastructure)....even though lacking in the ability to 
delegate.

However, I'm a little wary since at the moment there seem to be just a 
few sources of info or proponents (even though their arguments seem 
convincing to me) when it comes to SPKI.

I am also not aware of any products or PKIs that use SPKI certs.  I 
would really appreciate if someone could refer me to instances of actual 
usage of SPKI certs.