Is it possible to manually sort items from Views? I want to be able to define which content goes first and which one's last.
DraggableViews was designed for just this purpose.
The best I've found is to add the integer field to your content type. Then just number your content items in the arbitrary order you want them. When you create a view, you can use that field as your sort, and update them any time. You can even reuse numbers to make a nested inner-sort, so all items with number 3 are sorted alphabetically, for example.