If your IT dept have installed Certificate Services Web Enrollment, you can browse to https://your-server.com/CertSrv (accept/continue on the certificate error), authenticate as any domain user, choose "Download a CA certificate, certificate chain, or CRL", then on the next page choose "Install this CA certificate".
Originally Posted by dannns
This makes the process of trusting a private certificate authority nice and easy.
Actually, whether this will work from anything other than Windows Internet Explorer is something I don't know. But at least you could install the cert on your XP computer then export it via mmc certificate management and send it over to your phone via either bluetooth or usb.
I have to say, this is one of my pet hates. I'm a bit upset that Palm have not implemented a "accept permanently" for self-signed certificates. Nokia's Mail for Exchange used to be a pain like this, but now it will accept a self-signed cert permanently, and so do Android and the iPhone (my iPod touch v2 does anyway). Windows Mobile sucks horribly too in this (and every other for that matter) regard.