DNS based Website Failover Solutions?

Chase asks: "I run a couple of websites(including for my work). I'd like to have a backup web server that people would hit when my server goes down. My primary host is on my companies T1 line and even though I've had my server die once the most common reason for my sites to be offline is that our T1 goes down. I've looked at the High-Availability Linux Project but it seems that almost everything there is for failover using ip takeover which isn't an option if my network link dies and my backup server is on a different network. ZoneEdit seems to offer what I'm looking for but I'm wanting a do it myself solution. The only software I've found is Eddie and it seems to have stopped development around 2000. I know DNS based failover doesn't give 100% uptime but with a low cache time and decent monitoring it seems like it's the best solution for having my backup server at a differnt location and on a differnt network. Anyone know of a good solution? (Using Linux and/or Solaris hosts)"