ArcMap should have a scale slider based on the ArcGIS.com scales, not just a drop-down menu. You should be able to move from scale to scale with only one click. Having to use the pulldown menu for each scale change is annoying.
Well, I just realized that you can click an option at the bottom of the scale pulldown menu that will make the scroll wheel on your mouse only scroll to the scales in the list. I can't believe I didn't notice this option before. It's very useful for viewing maps with ArcGIS basemaps in the background, since they only display well at the ArcGIS.com/Google scales. I wanted to mention it here in case others had overlooked this option like I did. Given that this tool exists, I'm not sure a scale slider is needed after all. It may come in useful in some situations, though.
