Please feel free to ask for clarification of my question.

Consider this scenario:

A charitable organisation has funds which it distributes to research projects
it deems worthy of support. The recipients receive funds over the
course of 12 months. The recipients sign an initial contract to agree
to the funding arrangement and then, from time to time through the
year submit progress reports which are also signed. This amounts to
approx 5 interactions in a year. The recipients typically receive
funding once and then never again. The funds doner deals with approximately
150 projects a year.

It would improve matters if both initial and progress report signing
could be done electronically.

Please provide examples of key/certificate distribution in such a situation.

To refine my question I would just say the following:

1. I am familiar with situations where employees are issued with a
'smart card' which they use in a card reader next to the client
machine to activate a client certificate. I believe this (and all
other hardware based solutions that I have heard of) is not a good
approach for the current scenario due to the low frequency/short
duration of usage by the fund receipients.

2. I appreciate that a certificate could be emailed to the fund
receipients from the fund donors. However it seems to me that (A)
there is a risk of the email being intercepted and (B) upon receipt
the certificate is stored on the client machine and so effectively
"belongs" to the machine rather than the person. However I appreciate
I am ignorant of many aspects of this situation and so if the
researcher is able to offer a credible approach in this area I would
be interested to hear of it.

3. I imagine that some/all of the desired functionality could be
achieved by simply distributing a userid/password pair which was
entered into a SSL encrypted web page. Clearly secure
distribution/storage of userid/password is an issue here.

Would appreciate examples of key/certificate distribution in such a
situation as I have described. 

thanks