Two-way Communications

I’ve been researching how I can stay in touch when away from the computer and when the person who wishes to reach me is also away from emailing capabilities (or more importantly, not even a big emailer as luck would have it that most people I know locally are that way).
I looked into a two-way pager in which comes with a phone number where a person can call and leave a message with an operator. The operator would page me with a text message. But Paul believes that it would be just as difficult as calling me through the relay operator.
I am at my wit’s end. I want to be reachable to friends, family, colleagues without putting too many hurdles in front of them. Suggestions appreciated and will be shared.
What I’ve used / tried: I had a text pager for three years and got text messages fewer than 20 times during that period. I had a cell phone that could get text messages, but I didn’t promote it since I had a PDA with a modem at the time and could check email and it sufficed. Since then, I don’t have that set up anymore because the network is no longer available. But it still required using a computer or other email system to send a text message to me. I want to reach those who aren’t regular emailers.