ArcSoft Panorama Maker 6 3D (for Windows) is available for free when you enter coupon code COMPUTERBILDPMK at checkout. There doesn't appear to me to be any catch (i.e. you don't have to provide any credit card info, etc.), though you do have to provide an e-mail address. The "normal" price for this software package is $70. The coupon does not appear to work for the OS X version of the package. I haven't really used this software, but it looks to be at least as good as Hugin, which is a free, open-source image stitcher. At this price, I'm willing to give it a try.