So what can you do with the Highrise API? You could create useful things like Dashboard/Yahoo/Vista widgets for quick contact lookups or adding notes or tasks. You could write a tool to sync Highrise with Outlook, the Mac Address book, Plaxo, or your mobile phone. You could make a Highrise Quicksilver plug-in like this Backpack Quicksilver plug-in. There are a thousand ideas out there waiting for you. Here are some of the things developers have done with the Basecamp API.
Let us know what you build and we’ll happily help you promote it to our Highrise customers. Have fun and build something useful!