I rarely bother with labels, but sometimes it would be nice to toggle them on/off. Something like the
Pause Drawing button, except that it would only turn off labels (all labels in all layers...not just a single layer).
You can turn on dynamic labels for multiple layers at one time by opening the Label Manager and checking the box next to each layer.
Suggestion: Set Scale Ranges
Some labels are most useful within a given scale range. http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Setting_scale_ranges_for_label_classes