You can use the command line version of HTTrack on your Mac. I've worked out
some instructions on how to install it on Mac, as well as basic use of the
command line version. Look to the HTTrack manual for further info regarding
advanced options and filtering. 
The instructions were made as part of a test of several different kinds of
archiving software as tools for internet researchers: 

<http://www.cfi.imv.au.dk/eng/pub/webarc/>

The Mac instructions are part of the test of 'WebHTTrack'. The version I
tested was HTTrack 3.33-beta 3 – a lot of the problems that arised during the
test are solved with later versions! :-)   

By the way, at first when starting to use the command line version of the
programme I also missed a graphical interface. Now I love the command line and
get a little irritated when using it with the GUI on Windows,  as the
commandline makes it much quicker to launch an archiving process (!) and
because it lets me automate archiving tasks via scripts. 


Kind Regards, 
- Bo Hovgaard Thomasen
Graduate student, Media Science
University of Aarhus, Denmark