"triplet feel" symbol

[Federico Bruni]

I wonder if it's possible to tell lilypond to print the "triplet feel" 
symbol at the beginning of the score.
I don't care having swing midi, I need just the symbol.

I mean, something like this:
http://3.bp.blogspot.com/_TG7cLMAyug4/STO6exsyCuI/AAAAAAAAAA8/l2XfxJRpaDI/s320/triplet_feel_image.png

There's any command to get it?
Or should I use an .eps image?


Cheers,
Federico