Does anyone have experience or suggestions for setting up an automated dialing system? I am toying with a project that would provide automated phone appointment reminders to clients based on a daily feed of phone numbers exported from my CRM website for my cients.

Is there an open source solutions ala asterix that could accomplish this out of the box?

What about server hosting for this type of environment?

Any help or advice would be much appreciated.

I am also looking at some solution where a visitor to the website feeds in his number in the text box and clicks on the connect button and two calls are initiated connecting the visitor and the vendor.

We are looking at asterix too, will inform you incase we have success.

Asterisk would work for the automatic dialing out / appointment reminders.

http://www.voip-info.org/wiki/index.php?page=Asterisk+auto-dial+out+deliver+message

Ideally you'd want to have a script parse your feed at a set time in the morning, and queue up all these calls by adding them to the Asterisk spool. I imagine you'd have to parse the times from the feed, and assemble a spoken time. ie:
- play "Hello. This is just a friendly reminder from company name that you have a meeting"
- today.gsm/tomorrow.gsm
- at.gsm
- digits (9.gsm h-30.gsm a-m.gsm)

Thanks very much for the info and links. I have never used Asterisk or any kind of VOIP.

Do you know if there are any affordable Asterisk hosting providers?

lylix.net is the place you want to contact. I have a VPS with them and I am very pleased with it. They can do complete custom systems and will make it do exactly what you want.
PM me if you want any details.