What Mac OS X version and what exact/specific Mac (month/year of purchase, model) do you have what exact/specific problem with?
I assume, you have a Mac without Firewire (Unibody White or Aluminium MacBook), thus the "stupid" (though it is not) TDM is not applicable for your purposes of salvaging your data.
Have you considered removing the HDD and putting it into an external HDD enclosure for 2.5" S-ATA HDDs connected via USB to either a Mac OS X or Windows PC?
What about an Archive and Install with a Mac OS X version prior to Mac OS X 10.6 Snow Leopard (if the Mac came with a Mac OS X version prior to Mac OS X 10.6) or a simple reinstallation (without deleting your data) with the Mac OS X 10.6 grey Restore or white Update DVD?