Mobile for the elderly

  There's an entire generation out there that would desperately need mobile phones, but they are more or less barred from their use. I'm talking about elderly people who would love to have a mobile for certain situations, but today's phones are so small and the buttons even smaller that they simply can't use them.
  What I am thinking of is a simple device with just a couple of picture buttons - one for calling the doctor, one for a taxi, one for the grand daughter etc. The grand children (or the mobile shop) would program those buttons once and even old people with bad eyes and shaky fingers could easily handle such a device.