The stock Lucida Grande font that the iTunes widget uses was looking kind of boring to me, so I went in to see if I could find where to change it. Sure enough...
Navigatge to /Library/Widgets, and then open the package contents of the iTunes widget (control-click the widget and choose 'Show Package Contents' from the pop-up) after setting its permissions to Read/Write via the Get Info window. Now open iTunes.css in your favorite pure-text editor.
The fragment of code we're looking for is this:
#titleDisplay {
color: #393F21;
font: 11px "Lucida Grande", sans-serif; text-align: center;
position: absolute;
top: 33px;
left: 115px;
width: 128px;
height: 15px;
overflow:hidden;
white-space:nowrap;
text-overflow:ellipsis;
}
Simply change the font entry to whatever font (and size) you'd like. I have mine set to Hei; I love that font.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20051222154624187