Here’s an interesting survey that I recently stumbled accross that’s very useful when determing which fonts are “web-safe.”
“How sure can you be that the font you specify will be present on the end user’s machine? This is the latest cross-platform snapshot of the Code Style font survey and should give you greater confidence in selecting a font.”
The following is the results of the “Full combined font survey” of font availability accross different platforms:
http://www.codestyle.org/css/font-family/sampler-CombinedResultsFull.shtml