Get a pc
No, don't get a PC, Blockland runs stuffty on them. On Mac, it's the same. Do what you would for a PC. If you have Blockland on a Mac, it runs faster, more graphics, and much less lag. Vista especially sucks with Blockland, I wish I had a Mac.
I tried the method and it doesn't work! Maybe if badspot responds, he might be able to tell me.
I mean really Badspot makes most of the downloads of blockland for mac and dosen't tell us a thing on how to port forward with them.