Click on the applications icon. On the apps page, click the menu button and select customize. Long press which app you want and put it in the dock. You cant change the Home/App button but the other three you can.
This does not work on my captivate. after I click on apps, then click on the menu button, all I get is a large button that says "View type". There is no customize button. I can't figure out any way to drag any app onto the bottom dock.
ok, i got it. you got to click on View Type and then select "customizable grid". then you can change the home row buttons as described above, except you hit "edit" not customize.