Any way of printing pieces of large maps with regular sized letter paper for later assembly?

Hey guys, I've recently been inspired to try my hand at making maps for D&D campaigns, and since I have a regular old printer I wanted to find a way to create large maps using standard sized letter paper. Each leaf of paper could be part of the map and one would simply print out the other parts of the map and match them to complete said map.

I'd be very interested in knowing whether there is any software to aid one in doing this or if anyone had tried a similar method of printing maps.

Edit: The Rasterbator and Posterazor are perfect for what I need. Also, I did a bit of digging, and found this neat little online app, also available for Android and iOS. http://www.yeoldemapmaker.com/