I use Nokia N78 smart phone all the time without a data plan. It has Wi-Fi so I could get the Internet and emails at any place where Wi-Fi is availabe. It has free Nokia maps (almost the whole world) stored in the micro SD card, so that I could access map and GPS at any place and any time without a need of Internet connection (in contrast, other smart phones, such as iPhone and others, require Internet on the go). This phone has sometime substituted my Garmin GPS when I travel.
I just bought Nokia N97 Mini for my daughter. She also enjoys the phone in the campus where Wi-Fi is everywhere. She told me that she could do emails, Facebook, and watch Youtube in the cafeteria. Of course, there is no data phan in her phone either.