I still use a 3s.
3Gs? My original iPhone, bought on the first day it was available on June 29, 2007, was finally retired as a phone, after being handed down through various family members, last April or May. . . but it is STILL being used as an iPod by my 3 year old granddaughter. It is on it's original battery, which has never been changed, and has been in continuous use for 7 and a half years! That batter still takes a charge and holds about 80% of the standby and usage time it originally had. Utterly amazing. So much for all those naysayers who claimed the original iPhone battery would have to be replaced and would be a problem, being a non-user replaceable item. . . from day one.