I use a LG100C from TracFone for emergencies... it's only a 2G phone, but definitely NOT a current model.
Still works though, and I only need to charge it about once every 6 months (that shows you how little I use it).
You can find these on eBay... for example:
http://www.ebay.com/itm/271866219997Another phone I've seen recommended by a sensitive person is the Samsung M575:
http://www.ebay.com/itm/261914354272And for those who need some sort of smart phone capability, the Samsung Galaxy SII might be as good as you can get (at least in terms of anecdotal reports from people with ES). I got one of these for my wife:
http://www.ebay.com/itm/391081377513Marc