Here’s a musing.
Anybody notice the no-man’s land area of the dock? There in the middle where there lies the icons of apps you don’t have open.
On the far left you have the essentials (if you go by the Apple default) like Finder, Safari, Mail, iChat and then on the far right you have your newly opened apps which don’t permanently live on the dock. This leaves an area of unused icons in the middle.
I have way too much time on my hand, I need a new job.