One thing missing from Apple’s announcement of the voice-powered virtual assistant Siri two weeks ago was an API for developers to use to get their apps working with it. However there are workarounds, as Australian to-do app startup Remember The Milk has shown today.

You can get task reminders into your Remember The Milk account from an iPhone 4S using your voice and Siri. It requires a little bit of setting up, but once it’s ready, you’re good to go from then on.

It involves setting up a custom calendar linked to Remember The Milk’s servers and making it your default calendar (full instructions here). Then, as the video below shows, you can easily get Siri to add reminders for you without having to type a single letter.

Sure, this is only of use to anyone using this particular cloud-based task management service, but it shows that even without an API, there are ways for some developers to harness the power of Siri if they think laterally.

Another useful Siri workaround is to use it to tweet via SMS.