The Align & Distribute panel in Adobe InDesign is a handy tool for lining-up objects and distributing them equally in a specified space. But in order to distribute objects, you have to set the left-most and right-most objects exactly where you want them before using the Distribute icons in the panel.
A simple keyboard shortcut allows you to "eyeball" the distribution of objects
If you would rather “eyeball it,” you can do so simply by selecting your objects, grabbing one of the selection handles on one of the objects and hold the space bar down as you drag the handle. Rather than resizing your objects, the space between the objects will increase or decrease accordingly.
It’s important to note that the objects don’t distribute EVENLY automatically using this shortcut. In other words, if you have a quarter inch between the first and second object, and a half inch between the second and third, it won’t re-distribute the objects giving them equal space between them, it will only adjust the spacing already there proportionately.