WOW! I did not expect to get this many responses on this topic and positive ones for the most part.
Now I will tell you why I asked about seam rippers. As a fiber artist I am experimenting with an art form called Layer, Design/Draw, Stitch, Slash, Embellish or LDSSE. To create our art we layer fiber, usually 4 layers thick, than design/draw, stitch it, than slash around each, than embellish where the stitches are using fibers of various sorts and various type stitches. The projects come out awesome. We slash the fabric layer by layer mostly using seam rippers. I am about to experiment using other tools as well to see the ragged effect it will give to each piece of art such as those various shape scissors they use in scrapbooking, and possibly box cutters, surgical rippers and such.
Since I enjoy creating one of a kind rag quilts or rag looking art work this technique is something that intriques me. To most fiber artists it is called Stitch and Slash but I find Layer,Design/Draw, Stitch, Slash, Embellish,ie., LDSSE, a better description since that is what we do.
One fiber artist recommends the smaller cheaper seam rippers that we get with our machines. She finds those last longer and are inexpensive to buy. She has used larger ones and even expensive ones but states she doesn't feel they last as long or work better than those cheap inexpensive ones we get with our machines.
I've been looking on eBay and there are tons of them on there and you can buy in bulk those cheap inexpensive ones which you can toss after a while if it wears out.
You can get an example of what I'm talking about by going to Crafsty.com and check out the Stitch and Slash class being taught there. It is rather easy enough to do but can be time comsuming if you do such a project from start to finish. I love it and reminds me so much of creating rag type projects. Difference is with LDSSE you see the fabric colors evolve as you work the project.