The great thing about Citrix is that you can access company resources from almost anywhere. They have several solutions for remote access and thin client computing. They also have an ICA client for Apple OSX (Yeeehaaaaa).
I've been using the OSX ICA Client for a couple of months now to access my mail on the company intranet. Apart from some little quirks (like not functioning well when having two displays), the experience is good. Up till now.
Today, completely out of the blue came this error:

The error message suggests that I have changed something on my Mac, but not that I know. For someone who works with PKI, one would think that they would remember choosing NOT to trust a public VeriSign CA.
From this day on, you can install certificates from non-trusted CA's on your Symbian-based phone (like the Nokia E61) using this page euh.. this page.
UPDATE: it seems that most other phone brands and types work as well (the S40 based devices are left out... sorry).
All you need to do is make sure that the certificate is in the DER format. The webpage doesn't verify if the certificate is in the correct format. This is up to the uploader.
I created this page, because I work a lot with digital certificates, so I don't want to be bothered with the workaround described in the earlier post. The current version is quick-and-dirty (no error messages). I'll try to make it more user friendly in the next couple of days (like having the option of sending the URL to an e-mail address). Just make sure that you obey the guidelines shown on the page, and all should go well.
Feel free to add a comment on how to improve this.