To be honest, I don't post my phone # for two reasons:
1) I hate phones. Always have. Couldn't stand them when I was a kid, then I worked in Telecom/IS for a few years (and they drove me bloody batty!) I don't buy a phone unless I can turn the ringer OFF - we find it saves money that way. (My typical method of responding to a ringing telephone is by throwing hammers at it until it stops ring - usually only takes one or two hammers.)
2) Short-term memory dysfunction. It's easier for me to handle a job - particularly a custom - if I can roll back and look at the conversation. Else, I'd burn up far more notepads than I currently do, just in taking notes during conversations! Considering I want to get things right the first time, email is far either.
Throw in the fact that I usually keep bizarre hours, and calling me can border on unpossible. I have been known to arrange to make telephone calls when it can't be resolved any other way, but that's uncommon enough to be rare (I can be very patient, and tend to explain things rather well.) Such a call is invariably accompanied by the request, "If you have CID, please forget you ever saw this number."
However, I've taken to answering emails inside of 24 hours as a fixed policy, and I will invariably set the autoresponder when I'm on the road (although I understand Amtrak now has Wi-Fi on their trains...) But, doing it almost strictly by email seems to work out well for all concerned.
Yes, I'm probably missing business by not having a phone number posted, but I can honestly live with that.