I talked about iFontMakera while ago. If you haven't heard of it, it's awesome. If you have an iPad, definitely check it out. For example, here are 2 fonts I put together in about 10 minutes each. The app comes with font templates you can load as a guide, so I just loaded the typewriter font and traced each of the letters. Then I did the same with Helvetica. Easy peasy. To download, follow the link under each example.