I was recently asked if I had any suggestions for someone who doesn't like the feel of sisal. These are some great alternatives to natural fiber sisal rugs:
Sisal can be blended with wool and cotton to soften the texture, while still keeping the strength and durability of the natural fiber. You can find these at Restoration Hardware. (right)
There is also synthetic sisal, which looks like natural sisal, but is more smooth to the touch. You can find synthetic sisal rugs made with 100% DuPont nylon at sisalcarpet.com. This site allows you to order samples and create a custom rug for your home. (right)
Ballard designs offers a subtle, Moroccan patterned rug made out of 100% polypropylene, and can be used indoor/outdoor. It is extremely durable and soft on bare feet. (right)
Clicking on these links will bring you directly to the specific rug.
Hope this helps and thanks for asking.