Hardware is cheap, service contracts are not. Wi-Fi is plentiful and I know what stores have free Wi-Fi or even one of the 23 library locations in my county. Otherwise I have my pre-paid SIM for emergencies and Skype for everything else. I get GPS too. Take that iPod Touch that I waited for so long.Considering you can get an iPhone 3GS for free or an iPhone 4 for $99 sure they can. In fact if they can't afford an iPhone they probably can't afford the data plan that goes with any smartphone.
Failing that I can always get $30/month no contract from T-Mobile. I would rather save or invest my money instead of paying for little used data/voice services. Not to mention it functions just as well as a PDA without any SIM card at all.