2Do supports synchronising with CalDAV calendars such as iCloud, MobileMe, Yahoo! Calendar and self-hosted iCal / OS X Servers. The built-in Reminders app on iOS 5 in fact does something similar; it synchronizes directly with iCloud.
So if you have 2Do setup to sync with iCloud (2Do->Settings->Sync->Sync Method->Calendar Server (CalDAV)->iCloud), you will in effect be able to sync with the Reminders app. To create a reminder in 2Do using Siri you essentially:
- Create a reminder using Siri e.g. “Remind me to leave a review on iTunes for 2Do at noon today”
- Launch 2Do and tap Sync
- Voila. Your newly created task using Siri will now appear in 2Do
If you’ve got multiple calendars (Home, Work, Someday etc) and wish to decide where to create the reminder when using Siri, simply instruct “Add this to my ‘Work’ list’ when it asks you to confirm (i.e. when it says “Here’s your reminder… Shall I create it?”)