Only $6.99 from Shockwave ,,
http://www.shockwave.com/gamelanding/thinktanks.jsp
Get it here! (windows) On Sale! $9.95
http://www.reflexive.com/ThinkTanks.html
Buy it from Garage Games: (windows) (mac) (Linux) $19.95
http://www.garagegames.com/products/12/
Get it for (mac) GG version !--- (not on sale) $19.95
http://www.box.net/shared/qyf59zucsp
Get it for (Windows) demo from GG version $19.95
http://www.box.net/shared/uj5s4t7qh8
Get it for (Linux) demo from GG version $19.95
http://www.box.net/shared/pkq4eyqthf