As mentioned before, it is a good idea to keep the differences between the edit mode and the display mode as minimal as possible. In fact, it is a good idea to minimize modes where possible. In honor of this principle, a former manager of mine sported a vanity plate with the phrase "NOMODES". However, modes cannot be avoided altogether, as they do provide necessary context for completing specific tasks.
If you want to keep the display of items on the page as uncluttered as possible while still supporting editing, consider using a single mechanism to enter a special editing mode: Group Edit.
On the iPhone's home screen, the icons are normally locked down. However, there is a way to switch into a special Group Edit mode that allows you to rearrange the icon's positions by drag and drop. You enter the mode by pressing down continuously on an icon until the editing mode is turned on (Figure 1-13).
Figure 1-13. The iPhone has a special mode for rearranging applications on the home page—pressing and holding down on an icon places all the applications in "wiggly mode"
The Apple technique signifies that we have entered a special editing mode. When the icons become "wiggly," it is not a large intuitive leap that the icons have become loose and thus we can rearrange them.
Admittedly, the feature is not very discoverable. But it can be argued that it is straightforward once discovered. However, pressing the home button deactivates the rearranging mode. This really should operate more like a toggle. A better way to exit the "wiggly" mode would be to press and hold down on a wiggly icon. It follows the idea that you are pushing the icon back into its fixed place. Since deactivation is not the same mechanism as activation, it is a little hard to figure out how to go back into the normal display mode.
Another example of group editing is in the 37 Signals product, Basecamp (Figure 1-14). When sharing files with Basecamp, you can organize them into various categories. The categories are like folders. Clicking on a category link shows all the files in that "folder." What if you want to delete a category? Or rename it? At the top of the category section there is a single "Edit" link that turns on editing for the whole area.
Once the Group Edit mode is entered, you can add another category, rename an existing category, or delete empty categories. Notice the "Edit" link toggled to read "Done Editing". Clicking this link exits the group-editing mode.
Switching between edit modes should happen instantaneously. There is no point in making the user wait on an animation to finish before he can start editing.
The advantage of providing a toggling edit mode is that it keeps the display uncluttered with the editing scaffolding. The disadvantage is that it is less discoverable. This tension between discoverability versus readability is common and must be balanced by the needs of the user.
Unlike the iPhone example, you turn off editing in the same manner and location that you switched it on. The "Done Editing" link is in the same spot as the "Edit" link was. Since both are hyperlinks, they have the same interaction style. Interactions should be symmetrical wherever possible.