Grasscloth is popular and you see alot of it - but imagine these two spaces without the raffia wall covering. It would certainly be nice but not quite the same look. I think that since raffia has both vertical and horizontal texture the look is even warmer and more enveloping. (room above by Eric Cohler)
From the home of Dave DeMattei and Patrick Wade via House Beautiful here, photography by Jose Picayo
The raffia that Eric Cohler used was Phillip Jeffries, African Raffia Capri Natural (here). They also offer some amazing raffia's with a metallic finish and with stripes. In general, I think raffia would take stenciling very well too.
Besides well known wallcovering suppliers, you can find raffia from craft supply stores in a variety of widths - nice and cost effective if you're considering backing bookcases or covering a piece of furniture with it. The fine woven raffia cloth above is from Cane and Basket
These fabrics are from Franks Supply here. Notice the second fabric comes with the option of backing. I did read that's important for ease of hanging on walls.
My bed's headboard is upholstered in a raffia fabric. Do you have any raffia in your house?