Can’t remap that home button? Wish you had more than 4 hard keys? ButtonsEx is here to help!
ButtonsEx is a Palm OS 5 app that allows assigning shortcuts to every face button on your Palm–including 5-way navigation! It can also circumvent artificial limitations on some devices, like the TX only offering home button remapping to Applications or Favorites.
ButtonsEx explicitly supports Tungsten E2, T5, TX, Treo 650, Zire 22, and LifeDrive. A general version of the app can be installed on other OS 5 devices, but your mileage may vary.