SVG and embedded images?

Can anyone tell me if it's possible to embed a jpg or gif image (probably 
base64 encoded) in an SVG?  If so, what would the tag syntax be for this?

I read the SVG spec....but it seems that you can only refer to an external 
bitmapped image.

Thanks!

Andrzej Jan Taramina
Chaeron Corporation: Enterprise System Solutions
http://www.chaeron.com