XOSD displays text on your screen, sounds simple right? The difference is it is unmanaged and shaped, so it appears transparent. This gives the effect of an On Screen Display, like your TV/VCR etc. Comes with an XMMS plugin.
When I first glanced at it I declared it insane and not intended for mere mortals.
2010-04-20 - (version unknown) ∞
\echo "foo" | \osd_cat \echo "test" | \osd_cat --font "-misc-fixed-medium-r-semicondensed--*-*-*-*-c-*-*-*)" -d 1 \tail -f /var/log/messages | \osd_cat