In Mobile, when you create a message, there is a drop down to give you a list of Neighbors, Guild Members, or Friends, with check boxes by each person (and an Other option where you can enter 'random' names). You can go down the list and check all the boxes, with Guild Members, there is a short cut box to select all, with Friends and Neighbors, you would need to manually click all the boxes (easier than the browser where you need to type all the names). I suppose adding a visible list like that to the browser might not be that bad.