Often, you want to see what actual changes you have done. To do this, you can use the "Compare With" and QuickDiff functions.
Now, you can just hover the mouse over the QuickDiff marker line to see what was changed locally.
To set this permanently, you may use the Window > Preferences > Workbench > Editors > QuickDiff page, where you can select the "Pristine SVN Copy" in the QuickDiff reference list box: