yah. theres a lot that can be done.
but not all of it involves building or buying new stuff.
if nothing is above counter level, then most things are within reach. make sure walkways have enough room for canes, walkers, wheelchairs. wider doorways are nicer than most.
grip and grasp wanes in the later years - foam insulation over toothbrushes and utensils work amazingly well. looped rope pulls are easier to work than solid handles.
grab rails. everywhere.
home automation. those remotes with ginormous buttons? ugly as sin - but they work well. x10 controllers tend to be popular too (and cheap).
ramps. wheels are good. the curb/step is the enemy of the wheel.
accessible cabinetry is really fancy, but rarely needed if you organize right.
plenty of guidelines: http://www.adaptiveaccess.com/home_changes.php http://www.un.org/esa/socdev/enable/designm/AD3-01.htm http://www.wbdg.org/design/accessible.php http://www.vet.purdue.edu/cpr/bsd/building.html http://www.uniteddesign.com/accessible_plans.html
lots more stuff to think about - but i gotta get back to work