Suggest me a program to make photo collages

So I'd like to effectively print out one super big photo, but I'm going to have to do it by printing cuadrants.

Imagine one photo split into 5 columns and 4 rows for example, basically giving you 20 small photos that when reassembled give you the large original. What software can members suggest for this?

I use Zoner Photo Pro 12, and while it can do things like contact sheets, panoramas, 3D photos and other things, there is no easy way to split one photo into pieces.

Thanks
D

boohbah said:

there is a free online poster maker here

Block Posters - Create large wall posters from any image for free!

Just the job, thanks! :)