i've compiled a mac osx version of rdesktop from the
rdesktop distro and here it is.
its version 1.3.1
as you can imagine this comes with no support whatsoevah.
to install, download this file, get it untar'd ( tar xvzf rdesktop-1.3.1.tar.gz), cd into rdesktop-1.3.1 and then type 'make install'