I'm signed up for the newsletter that FontShop puts out, and they've apparently been working pretty hard over there. It looks like they have a new font-building application on their site that lets you build fonts (albeit on a grid) that work on both Windows and Macs. It's called FontStruct, and here's the link: http://fontstruct.fontshop.com. Once you've created your font, you can share it with the rest of the world to look at or to download. Or not, if you're shy.
Great for fontaholics.
And it looks perfect for the typography classes I'll be teaching this fall. I'll have to do a little FontStructing of my own before I unleash it in class.