I finally broke down and ordered this rotary arm gadget for my Olfa rotary cuttern. It's called a Removable Rotary Arm Guide and I first saw it on a blog post by Sew-4-Fun. I cannot find her post where she used it, but I did bookmark her answer to my question about it. I had never seen anything like it in my area and since her post, I've really kept my eyes open for it. I had found and bookmarked it at an internet store, but figured I had all the time in the world to buy it or get it as a gift. Fortunately, I noticed that it was going to be a discontinued item and since it's been more than a year since I learned about this wondrous gadget, I figured I'd best be buying it.
Isn't it neat when you learn on the internet from other sewists? I can really see that this will be useful for patterns that don't include seam allowances or where I want to add more to an existing seam allowance on a pattern--what a time saver! I can't wait to try this new tool out! I bought 2 of them, just in case!