One way to do this would be to Illuminate a white background (paper/canvas/sheet screen ) from behind with a bright spotlamp.
Place your subject in front of the backgound with enough distance to allow you to stop the lens down so your focal range is small - this will make your background blurred and will help remove any inconsistencies marks or folds on the screen.
You may have to place a quick wipe around the edges in photoshop to remove any tonal differences but thats easy enough when you crop the image and save for web.
Take limbo's advice... but i'd like to just tack something onto his comments:
The standard technique for getting that "this subject is in the middle of nowhere" look is to make sure the bottom of your white sheet or canvas rolls onto the floor and towards the camera... by having the canvas curve onto the floor instead of a canvas or white wall that simply ends at the floor, the benefit is three-fold:
You allow yourself more angles to take photos with, because if you just have a wall behind a subject, you're basically confined to taking a head-on shot.
You eliminate the line that occurs between the plane of the wall and the floor, effectively giving the subject the look that it's "in limbo" (no pun intended).
You have a background that is more or less facing the light source at all points. When you use a wall, the low part by the floor and the high part by the ceiling reflect the light at more acute angles, which will come out a little darker than the white in the center of the wall.
For best results with product photography on a bright White backgrounds try to use light Tents. (search Google for how to build your own Lighting Tent or for the wide range of commercial light Tents) Light tent Surround the object by a translucent material which is lit from the outside by two (as minimum to avoid dark sides or shadows) or more floodlights with 5000° Kelvin bulbs.
Larger subjects require larger light tents. You can construct a wooden frame and cover it with cloth or plastic sheets. When illuminated from outside, the light within the tent will be diffuse and nondirectional.
to reduce the grayness of the white background just try to increases the Exposure to +1 or +1.5
Light boxes or Tents is just Suitable for product's photography, there's big sizes but not as big as suitable for photographing people
For people photography you'll need at least: - One "soft box" and a Reflector or two soft Boxes - A metal portable background stand - White background paper which you could find it online or at any photography equipments retail.