Posteriza 1.1.1 build 345 click below to download it…
http://www.download.com/Posteriza/3000-2130_4-10485661.html?tag=lst-4-5
That is your best/free solution. I have used it before and it worked great! Lemme know if you have any questions. This is better than using photoshop or windows print if you want to print posters…