Calls vs....
One alternative would be to use your @agendas for this purpose. @agendas is a a very useful list, especially for those times when you might call, but could email, etc. As one poster pointed out, whether a call or email is best will change over time.
My @agendas list is the newest context for me to implement (very well, anyway). I do not have as many meetings as I have several items to bring up to the same person.
My @calls list is actually called my @phone list. I, like the OP, have a smartphone, and so the @phone context includes all updates, applications, organization, as well as telephone calls to make. As the @phone relates to calls, the actions usually contain fewer topics to discuss with people I do not deal with regularly.
@anywhere could work IF you really have your phone with you as often as you have on clothing. Remember the purpose of the contexts is to separate out items that require special equipment. I don't have a context list for things that require pen and paper because I always carry them. My phone occasionally gets set down.
Note that, for a person who relies on his/her phone for GTD, @anywhere could especially apply, because that person wouldn't know even what was on the @anywhere list without the phone.
JohnV474