Questions about the dock

1. How can I add my own launchers to the dock? I'd like to have a shortcut to xterm, and the icon of the running program is un-drag-able.
2. Can you make the folders on the dock retain their icons? Whenever I download something, the 'Downloads' folder on the dock turns into a thumbnail of the downloaded file.

When u run an App from Applications folder or anywhere else an icon will appear in the Dock - right Click on it and select Keep in Dock and it is there for next time.
2. make your folder in a finder window then right click on folder and select Make alias and drag alias to right hand end of Dock

The second trick works, thanks.

The first doesn't, since xterm is a subprocess of X11, and I managed to get it on the dock only once, dunno how. Now, whenever I run it, only the X11 icon appears on the dock, with xterm inside.

So have u tried making an alias of xterm and putting the alias in the dock?