Jeff and Eric have already told you about embedding raster graphics,
(convert to PNG, store in a <data> section). For vector graphics, it
looks like it might be convenient to convert to SVG and use XML
namespacing to embed the SVG directly in the middle of the document.
Like this:
<abiword>
<section>
<p>Here is my beautiful image:
<svg:svg width="2in" height="2in">
<svg:g style="fill: red">
<!-- ... Some nice path here ... -->
</svg:g>
</svg:svg>
</p>
<p>Wasn't that nice?</p>
</section>
</abiword>
-- Matt Kimball mkimball@xmission.com