Our other option is to get another DSL connection on our fax line, but of course that involves more cost than we would like. I don't quite understand the reasoning behind only allowing 1 static IP, considering we have a Juniper router that is pretty complex and can handle up to 6 (I think) static IPs. Obviously there must be other businesses out there (like web hosts) that would have more than 1 static IP, how do they get additional ones? If anyone knows of an ISP that allows more than one static IP per connection please share.
Something else we have looked at is Dynamic DNS, unfortunately I'm not convinced at this stage on its abilities, so if anyone has experience with it that would be great if you could share your opinion.