I found this program on the web. It says it's only for TomTom Go and not the TomTom Palm. But if we only need to download TomTom maps with the TamTam, it should work?

From their website:
"TamTam makes TomTom GO Mac compatible!
*With the release of the Mac OS X compatible program TamTam, we now offer a solution for the popular GPS navigation system TomTom GO for the Mac. (Please note that TamTam supports only TomTom GO and not TomTom Navigator for Palm/PDA)"