A few months back, we flipped the switch on Ta-da List for the iPhone. If you have an iPhone, just visit tadalist.com and you’ll see the iPhone version. You can access the standard web version with your desktop web browser. Both versions share data and lists.
Just Another Mobile Monday, a mobile news site, just profiled different iPhone to do list applications. The author says, "For those who want no frills and a very basic feel, I’d go with Ta-Da List."
In a Nutshell: Strong on ease of use.
Ta-da List is made by 37signals, the well-known company behind popular online applications like Basecamp (for project management) and Highrise (simple CRM). It’s described by the company as ‘just ultra-simple, easily sharable to-do lists.’
That description is accurate. Ta-da List is very easy to work with. All its screens fit well on the iPhone and feature a simple, minimal design feel. It uses large buttons to help you quickly add a new task, edit an existing one, and switch back to list views.
Currently you are not able to add a priority, due date, or notes to a task. Also, if you want to re-order your lists you need to be on a desktop browser, where you can just drag and drop to re-arrange all items on a list.
From the desktop, you can also mail yourself a copy of a list, and subscribe to be notified of changes to a list via RSS.