This has been a very interesting discussion to listen to. In the first place, I don't have a cellular so it probably gives me a different vision from other people, since the majority of them have one. I already had one but I couldn't use text messages and it was because I was working for a company with which I was travelling in car all around Quebec and New-Brunswick so people had to be able to talk to me from far away. Of course, I could and I did use it for personnal purposes and I enjoyed it, but I'm not sure I would be ready to say that it's become impolite to call someone at home directly.
First of all, everybody doesn't know your phone number and you usually don't give it away for no reason. People can obviously find it in a phone book, but then, they likely have a good reason to talk to you. Also, I think it's almost the same thing as going to people's houses, yet it is more convenient since you don't have to do all the way to get there, you just have to pick up your phone. I'm making that comparison because sometimes you will clearly disturb people by calling them although you must be aware of some basic principles when you own a phone.
The first one may be that you must not call at ridiculous hours (during the night for instance or during meal times). This might get annoying for people receiving the call and they surely won't appreciate the discussion. Furthermore, if it looks like the person does not participate much in the conversation, just don't push it too far, he probably doesn't want to talk to you at that moment.
As I said earlier, I don't think that calling people is rude or impolite if you do it properly. Besides, receiving a text message is supposed to bother you as much as a phone call if they are written for the same reason. If you prefer to receive the same information in a message instead of a phone call, it's because you are becoming a hermit and that you begin to get cut off from social relationships. If it makes it just more convenient when you're away from home, that's okay. If you only have a cellular or if it is about money, of course it is understandable, but don't tell me you will text someone to warn him that you will call him if it's someone you're supposed to know well.
