Take a good picture of the wallpaper, then print the picture on fabric.

http://www.instructables.com/id/Inkjet-Printing-on-Fabric/

Although, personally, I wouldn't go for an exact match. I think something similar but a little off and in a different color, might work better:

http://www.designsponge.com/2011/06/diy-project-ikat-print-pillow.html#more-105565

YMMV, of course!

Could you cut the wallpaper with an exacto knife into a stencil and use fabric paint?

Find the name and maker of your wallpaper online to see if they make a matching fabric. There is often a coordinating collection of fabrics to complement your choice.

Check with the manufacturer's rep -- often times there will be coordinating fabric and wallpaper. But no, I would not try to turn actual wall paper into an actual pillow.

Scan or take a good photo of the pattern, and have it printed in a smaller/larger scale at spoonflower.com. Then it's not an exact match, but "goes" together. You'd only need about a yard of fabric for a couple pillows - pretty affordable.

I don't think there is a way to do that other than the stenciling suggestion above.

If you want an exact match you could maybe scan the paper and ahve it printed onto fabric. I know there are companies that can do that, but I don't know the legalities of printing someone else's design.

I would follow the suggestion to check for coordinating fabrics, or look somewhere like Calico Corners, fabric.com, etc for something that you like.

I agree with all the other comments about turning it into fabric. If that doesn't work out, you could use some of the left over wall paper to line the inside of a coffee table tray, or make a cover for a hard bound book. THere are other ways to incorporate the pattern you love into your living space. Good luck

You could use it to trace over to make a freezer paper stencil for printing. Freezer paper is better than using the wallpaper directly, because it will stick temporarily to your fabric as you paint, giving you nice clean lines. Here are a few tutorials:
http://meganmonday.blogspot.com/2009/05/freezer-paper-stenciling-tutorial.html
http://sweetthingdesigns.typepad.com/craftymama/2009/03/my-entry.html
http://angrychicken.typepad.com/angry_chicken/2006/03/little_elf_shir.html
http://goodnessrecycled.blogspot.com/2010/03/how-to-make-camp-half-blood-tshirt.html

I'm not sure how they are doing it, but have been seeing purses and bags made from recycled paper - like the comics, somehow turned into a fabric like substance - pliable, but tough. Not sure it would be a very comfortable pillow though - a bit plasticky. Like this:
http://shop.nubegreen.com/index.php?product=NEW-ACC-CLU&shop=1&c=60

This will work better than taking a photo. Have the wallpaper scanned and printed on (or heat transferred) to fabric. EASY.

If you want an exact match, the above comments are spot on. However, there are several ikat pillows on Etsy that are very similar in look (although I have to agree with MarlyK that I wouldn't want an exact match)
Examples: http://www.etsy.com/listing/73380731/ikat-coral-pair-on-linen-flax-pair-of

http://www.etsy.com/listing/75266055/a-pair-of-little-9x18-accent-pillows

http://www.etsy.com/listing/75682759/16x16-blue-and-cream-ikat-pillow-cover?ref=sr_list_8&ga_search_submit=&ga_search_query=blue+ikat+pillow&ga_search_type=handmade&ga_facet=handmade

I'm just anti-wallpaper...I've taken down too much of it over the years.

is there anyway of converting the left over wallpaper into pillows with the same design?

I doubt it. Wallpaper is designed to be glued to a hard, stationary surface, not to flex and bend on a soft surface. The paper would probably crack and flake very quickly.

One option might be to use little panels of wallpaper within a fabric pillow cover, in the same way that Indian fabrics sometimes have little mirrors and other inflexible objects woven into them.

Try spoonflower.com

you can buy some iron on sheets at the office supply store so that you can go to Kinkos or Staples and do a color copy of your paper, then print it on the iron on sheets, then lay them onto fabric and iron your pattern onto a solid white or cream fabric, then use that to make a pillow.

the issue will be that usually the images are not as vibrant as the original--it may be more faded looking depending on what you iron it on to...and the size--these sheets are paper size so you may want to sew a border of some solid around your transferred image to make a decent sized pillow.

here is the type of thing you need to do the transfer--you can do it with a scanner/laser and inkjet--i've just had good luck with color copiers--and the surface is bigger so i can scan more and size things.

http://www.discountofficeitems.com/office-supplies/paper-pads/brochures-specialty-paper/iron-transfers/avery-dark-shirt-transfer/p1430.html

This damask design is very common and most of the major stencil companies sell stencils that are a close match if you do not want to make your own. If you do want to make your own stencil, it is easy enough to just lie a sheet of mylar over the wall paper and trace this design. Stencil with fabric paints and perhaps embellish with some crystals!

Thanks to everyone for all their suggestions! These are great ideas!