Contexts

Because you probably have many items, you can organize these items in contexts. David Allen organized the items in his "Getting things done" system in contexts like: home, work, at the computer, at the phone, on the Internet, grocery store. This way, you can find the appropriate item according to the context that you are in.

In this application (NextAction) you can create sub contexts. For example, you could have a home context, which you sub divide into computer, phone.