settings/language & keyboard, scroll down to "keyboard & input methods" hit LG Keyboad (I'm assuming you're using) and then under General tap Keyboard height and layout.
**EDIT** oops. looks like there's a no go for that, sorry I have the google keyboard and you can stretch it if ya wanna....
**ANOTHER EDIT** my bad, you're talking about landscape- follw the directions above, and then hit "Keyboard type in landscape"