Question: This is not just gnome terminal, but pretty much all gnome windows: When you hold the "alt" key, you can press the first letter of one of the menu items. This will let you scroll that menu without clicking on it directly.

This is okay on any other window, like say Firefox, but on gnome terminal, it steals the keys I use for emacs!! There is very little chance of me learning a new set key combinations if I can avoid.

If I can't isolate this just to gnome terminal, I'm fine with that.

Answer: 
Edit > Keyboard Shortcuts..., and uncheck "Enable menu access keys".
If you want to do it globally, you can try this method ([source](http://ubuntuforums.org/showthread.php?t=1735533)):

> 
> To disable mnemonics you should create (if it doesn't already exist) ~/.gtkrc-2.0. 
>  This file should contain the line gtk-enable-mnemonics = 0 (you can
>  add other GTK settings if you'd like). Then, restart for the changes
>  to take effect (you may be able to log out then log in instead).
> 
> 
> The alt key will still make menus appear in some cases, but the
>  mnemonics are now disabled. Hoorah!
> 
> 
> 

EDIT: this method no longer works. I filed a [bug report](https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1113420) regarding the OP's question so we'll see how it evolves.