Information about chorded keyboards - there is a precedent.

Chorded (Chording) keyboard history/references:

http://en.wikipedia.org/wiki/Chorded_keyboard

http://en.wikipedia.org/wiki/File:Chording_Keyboard.png

Chorded_History_reachinformation.pdf

Chorded_History_BuxtonInputTheoriesPreface.pdf

Chorded_History_BuxtonChordKeyboards.pdf

Chorded_History_BuxtonIllustratedTour.pdf

Chorded_History_BuxtonMultiTouch.pdf

Book: Text entry systems: mobility, accessibility, universality By I. Scott MacKenzie, Kumiko Tanaka-Ishii, 2007 - 332 pages, (Morgan Kaufmann Series in Interactive Technologies) (Paperback)

Chorded research:

Chorded_Research_chordite.pdf

Chorded_Research_kittytech.pdf

Chorded keyboard web sites:

Chorded_WebSites_about.htm

Chording keyboard manufacturers (current, as of August 2009):

Chorded_ListMfgs.pdf

http://www.tifaq.org/keyboards/chording-keyboards.html