One possibility would be to use CallWave (www.callwave.com). This is a program that functions as an "internet answering machine." If a call comes in when you're on-line, you'll get a ring on your computer and your caller can send you a message that is recorded and then played on your computer. CallWave needs "forward on busy"; my telephone company charges 75 cents a month for this. I have the freeware version of CallWave that limits messages to 30 seconds; more options are available from CallWave's website.