CALLING ALL RUG MAKERS - can I interest you in a new challenge, please?
Since this problem might never be solved, a simple and smart way to transform smaller mats into the large rug you have been looking for, is with a needle and thread (as shown below). This could work perfectly with square mats (in a living room or bedroom) or rectangular mats (down a long hallway). The fun of this, in addition to not having to break the bank, is the color combination's you have at your finger tips. And since the stitches don't need to be perfect (personally, I like it a bit sloppy) this project is actually something that you really could do on your own...opposed to something you like but would never attempt (I know you know what I mean :). So stop making excuses and get sewing, this HOW TO is gonna make your feet dance!
Cost Plus, CB2, Ikea, and Overstock, all have well priced rug options that will help get you started.
Via Room And Serve