Well here is a unique project that I am thinking about, converting a quilting machine to cnc. There are a few ones offered on the market but that would be no fun, I would rather build it myself.
Here are the parameters the x-axix is 120" long and the y-axis is 24". There is no z-axis to worry with. Resolution needs to be in the range of 1/100 of an inch. Sounds easy, right? Ok well to be productive it needs to sew at 3 to 4 ips and possibly 4 that's 180 to 240 ipm, with indexing moves above that. The biggest issue I see is inerta, The machine itself is about 35lbs and the y carriage will be another 5 to 12 lbs at least (it has to carry the complete y-axis system). For instance when running into the point of a star the last stitch is the last stitch before direction reversal, there is no radius or room. Been thinking about belt drive on the x-axis as it would be cheap, easy and give the required resolution, probably rack and pinion on the Y as it would be compact. So how does one calcuate how large of a motor will be required? Either stepper or servo. It there acc and dec on steppers? Does Mach3 read ahead and allow you to slow down when necessary?
JUst a bunch of questions and an Idea that I am dying to try, I know its being done, but I wanna do it my self.

thanks guys

For motor sizing etc, check out the Kollmorgen free graphic sizing, most servo manufacturers supply one, there are many out there.
You may not want to go the 'exotic' route of motion card, but here is a Galil Demo of quilt machine. http://www.galilmc.com/support/motioncode/animations/quilt_stitcher.swf
Al.