Did you know Comcast HSI has an "Economy" tier for $24.95/month?
My parents are a great candidate for the Comcast HSI Economy tier, since DSL service is not available in their area and they refuse to pay Comcast $42.95/month for their next highest tier. I'll definitely be giving mom and dad the hard sell to take the plunge since it will be a pleasure to actually be able to call them without getting a busy signal for hours at a time.
I also may try to sweeten this deal by getting them to purchase a Comcast cable modem self-install kit at retailers like Best Buy and Circuit City, since they frequently offer it for free after rebate when you activate High-Speed Internet through them. A nice bonus would have been the $75/$100 rebate and free month of service that Dell used to offer when ordering High Speed Internet Access through a link on their web site, but it looks like that deal has dried up.