well to explain the situation in detail as far as i understand it, here goes.
newtons use two types of infra red protocols. the newt 100-130 use sharp IR. this is a proprietary protocol used by sharp made devices including newtons and sharp organizers and stuff, overall its rather slow and old. the newton 2000, emate and 2100 are able to speak sharp ir as well as IRda, which essentially all new infra red devices talk. this allows the newt to speak to HP printers, other newtons, laptop computers, and now with the advent of the OBEX transport by
smart dog software newts can also talk to palms, i beleive some wince devices and some other devices. anyhow, the problem is, cell phones and ir modems and stuff use a part of the IRda protocol called IRcomm. the problem here is that the newts dont have that part of the IRda stack implemented in their software, so you cant use IRcomm devices. it is possible, and i beleive reletively simple to make the software, and smart dog has expressed intrest in producing it but they need more feedback to make it. so email them telling them u want it too.
and yea, if u get a 130 it could never talk to anything but other newts or some ir pods for desktops. for IRda u'll need a newtonOS 2.1 machine.