Allowing more filetypes to be uploaded

Hi there,

Is there a function in WP, or something that I can add in my wp-config.php to allow the upload of different filetypes.

With all due respect, I think the idea of being able to limit certain type of files in my own WP is a great idea. But that shouldn’t be enforced.

I want to be able to upload .XPS files (Microsoft’s sort of PDF file). How can I add this support in my WP installation?

Thanks in advance,
P