Just read a disturbing blog post (crimefictioncollective: WTF? Why That Font?) that warns authors against publishing using 'free' system fonts. If you publish stories using the system fonts from M$, Linux, Word or OpenOffice (or even 'free fonts' sites which collect processing fees), you could be liable to copyright infractions. (Many 'free fonts' require processing and shipping charges to earn their income.)
Ernest and Switch, you're probably safe since we discussed the 'most common fonts for ebooks', but Ernest, I'm not sure whether Palatino Linotype is 'free' or not.
I think I'm safe since my books are mostly published with Garamond (listed as one of the six fonts available for publishing ePubs), but I'll have to check to see whether that's free or not for publishing.