I was needing a cloud based todo application with support for the iPhone, preferably native. I need something that I can adapt to my workflow and doesn’t change it completely (as for instance OmniFocus). After evaluating several web applications I decided to use todoist . I thought about Things for Mac & iPhone but I have read some bad reviews about syncing and it has no web support, making it unusable on work. todoist has a freemium model so is free unless you want the extra features (notes and SMS alarms). On the mobile side, I have bought Doings, an iPhone application that works with todoist and can sync back to it.
And by the way, happy new year.