Will browsers support multiple proxy servers?

We do not have a firewall but run a proxy/caching server to improve
performance and save network traffic costs.

However it is a single point of failure because we don't have an automatic
failover strategy and no out-of-hours coverage. What I would like is to be
able to configure the browsers with at least two proxy servers (one as the
default) just as one does with DNS nameservers, and run a proxy server
(without cache) on another system just in case the main server fails.

Has this been discussed before and have Netscape or NCSA indicated it might
be a possibility?

Monica Berko                                     Email:Monica.Berko@anu.edu.au
Centre for Networked Information and Publishing  Phone: +61 6 279 8114
Australian National University                   Fax:   +61 6 279 8120