The 37signals guys are quite fast. We only mentioned it few days ago, and now they’ve released the iPhone optimized version of their popular Ta-da list service. If you’re not familiar with Ta-Da list, it is the Web app/service that allows you to make quick lists. For instance you could make shopping, gift, or a to do list in just a few minutes. It’s free, and you can try it from here — from your iPhone or from a desktop computer.