No quarters needed! I love it! The games are usually really, really close to their originals and free to download.
At VP Forums you'll be able to learn more about installing a pinball machine emulator and finding ROMs for you to play! I have been able to find every pinball game I have ever enjoyed playing. You can visit the site at http://www.vpforums.com/.
Here is a screenshot of one of my favorite pinball games, Medieval Madness: