Found the @font-face reference page in the MDC and read a bit about the three main types of font formats supported in Firefox. TrueType and OpenType are supported in Firefox 3.5 and Web Open Font Format is supported in 3.6.
Adding support for WOFF fonts is nice because the font is compressed which saves bandwidth, and Microsoft is expected to add support for WOFF as well in the future which will make WOFF the defacto standard probably.
So I started to put together a test page to use to see what browsers I had support the @font-face rule and see just exactly how it works for the end user and I noticed on the MDC page a link to a page of examples. So why spend time putting my own together when there is a perfect test case page already available ! It tests multiple different fonts in multiple different sizes and combination’s of bold, italics, small caps, thin, light, bold + italics, etc.