I have regular DSL (Qwest) and would like a simple solution like dialing a phone number using a standard modem, and sending the voice message. Can this be done? If so, where can I find the specifics on using a modem with Asterisk?
Not really. You need a real FXO port. Your cheapest option might be a X100 clone, but they are not always reliable (they are rebadged versions of a certain type of voice modem). Digium TDM400/sangoma a200 are better bets.
Ok, but thats a bit expensive for something I am unsure of.
I have Nagios installed and found an article using Asterisk to report problems. For the time being, can Asterisk be configured to send the message to a sound card till I get a proper FXO device?
Astrisk can call a exten and you setup the voice mail up to send out to your email / SMS plus you can have a softphone on the pc which will ring or set to auto answer
No phone line needed
plus you could get outbound mins from someplace like connect.voicepulse.com and use the Voip trunk to send out the message to the PSTN