OK so about 2 months ago i got blockland working via crossover games (
http://news.softpedia.com/news/Download-CrossOver-Games-8-0-0-Supports-New-Games-Snow-Leopard-120853.shtml)
1. click the link and download crossover games 8 (note: this only works on crossover games 8)
2. download the windows version of blockland.
3. double click the file blockland.exe
4. if it doesn't open automatically in crossover games, click choose application and select crossover games.
5. install it (simple installer in windows almost like mac installer)
6. (optional) if you have backups or you're ad dons put you're addons folder in the blockland directory
NOTE: if you don't know where you're blockland directory is, click on manage bottles (in the screen the pops up when you open CO games)
click the bottle you installed blockland in, click "open C: drive in finder" click program files, click blockland, then there's you're blockland directory. I'd recommend you make a copy of the directory and put it either on desktop, or in you're dock. install addons the same as the mac version in addons. only downside, if you cant enable NAT-PMP (basically mac version up UPnP) you cant host. like me :(
Hope this helps,
MP7964 (MP6767[UN][TSS] in-game)