Asana is a task management tool created by a co-founder of Facebook and one of its early engineers. I've been using Asana since it launched out of beta last year, and have found it to be a very powerful web application and organizer in my primary field. Recently I have been finding uses for Asana in tracking family history queries and progress toward my First Families of Tennessee application.
Asana released an update to their iPhone application a few months ago, which has made it much easier to use on the phone. The application works great through mobile Safari on the iPad, but I like the speed of the iPhone app and use it for quick checking of tasks and storing information. It supports pdf documents as attachments within tasks, and it is an alternative to services such as Basecamp.
Below is a sample page showing my First Families of Tennessee prep work.
When I click on the Resident in Tennessee before 31 Dec 1796 task, it opens a view on the right (see below):
Below is an example of how I'm using Asana to track queries and future items to research. At any given time I have many queries on various lines that I'm researching, and it's easy to forget what has been sent out or what needs a follow-up if one doesn't keep track.