Actually, it is. By simply being a square cloth, it can be folded in various ways to accomodate your belongings. It eliminates the need for different kind of bags and bags in bags.
I said it's just a square cloth - but with a lot of art. You can enjoy different textile, color and motif. You can use different technique to wrap your belongings depending on the item/size. It has evolved a lot- Furoshiki can be used even as a tote bag or a baby sling! Such an entertaining cloth.
Because Furoshiki is an old style bag, it has been thought as an accessory for Kimono. Therefore people forgot about it for long time because we don't wear Kimono that often in modern society!
But the green consumers re-discovered it recently. New generation Furoshiki has wide variety in design and use.
I found a nice website in English. Ecoshikis, Portland, OR sells Furoshiki and introduces a lot of information about Furoshiki including how to wrap it.
This site is also interesting. It is by a Furoshiki-shop in Kyoto, Japan. Although it's all in Japanese, you can see a lot of graphics on how to wrap it and use it.