[XeTeX] Generating a PDF which is cropped to the bounding box?

[Adam Twardoch (List)]

Jonathan etc.,

I have a simple XeTeX script that produces one line of text. The line
(or the artwork, in general) has a certain bounding box. I'd like to
generate a PDF that is cropped exactly to the size of that artwork. Can
I do this directly in XeTeX? If not, is there any way to do it directly
using ghostscript?

Thanks in advance,
Adam