I got one of these fabric covers for my Kobo and I love it. It's not a sleeve, but that's mostly how I use it; if it's in my bag, I can flip the (otherwise secure) straps off the top corners of my ereader one-handed and pull it out, and then slip it back in (slightly less secure, but only slightly) when I'm done. It's been fantastic for all kinds of travel--subway, bus, train, plane, car, walking, you name it.