I periodically miss phone calls because the ringer volume was turned down to zero. The problem appears to be because of the the ringer volume button placement - it is VERY EASY to touch the ringer volume button when putting the Droid into the (Motorola) belt clip.
As a result, I try to remember to touch the ON/OFF button at the top of the Droid before putting it into my belt clip, which disables the volume button. It works, but I shouldn't have to do this.
I believe that the best solution would be to have a "confirm" option displayed on the touchpad just below the ringer volume bar that is displayed whenever the ringer volume button is touched. Once confirmed, the ringer volume button would be activated until the Droid goes on standby in another minute or two. This should only be for adjusting the ringer. If in the middle of a phone call, a "confirm" request would be a nuisance. The programming for this should be pretty simple.