Cultured Code's Things has been updated on both iPhone and iPad, adding a widget to the Notification Center. You can use the widget both the view your current tasks and start new ones.
The Things widget will show you the tasks that currently sit in the Today section of the app. You can mark tasks as complete from the widget, and Things will update next time you open the app. Create a new item by tapping the "+ New To-Do" button at the top of the widget.
Things 2.6 also contains improvements for the URL scheme, as well as the almost obligatory stability and bug fixes. The update is available for both the iPhone and the iPad apps on the App Store now.