What kind of phones do your parents use now? Do they text with you?
They both use Samsung SGH-A767 phones, which I admit are pieces of crap themselves, but they were both coming from motorola razr's last July (when I got the 3Gs), so I thought the phones were good enough to get them more acclimated to texting. Though e-mail is an interesting idea, they're just recently learning how to send pictures to our iMac through bluetooth and getting used to the iMac itself (lol). Plus, texting me is a great way to contact me while I'm in a class or at work, so I can respond to them without anyone catching me breaking the whole "no phones" rule every place tries to implement.
Also, every one of my friends text so much that I think we rarely call each other these days. So the messaging plan in my case is still a necessity, where as though they might end up liking Internet usage - especially if I got them iPhones as well - they don't see the need or even have a "want" for it.