People have often asked me how I take Ebay photos. This is the classic question of how to cheaply do what is somewhere between commercial product and copy stand work.
The simple setup above is what I use most of the time. It is cheap, quick and works like a charm. I use 4 pieces of white foamcore board to make up the 3 walls and the base. It is the cheap kind that you can get from the local craft store in the USA for somewhere between $1-4 a sheet, depending on where you go. To get the curved background, I drop in a piece of white posterboard. It bends pretty well and reflects nicely. I hold the posterboard in place with some rolled tape on the back of the posterboard.
For the lighting, I use one light overhead. This is frequently a SB-900 flash set at TTL +1 stop, shooting through a 24x24" Lastolite Hotshoe Ezybox. I have also used a sheet or an umbrella to shoot through, or another piece of foamcore to bounce the light off of from a window or flash. I have also used a halogen or fluorescent light and even just the room lighting. The softbox is much more convenient for when you want to accent specific areas of the product or just get the highlights in the right place.
If you have an assistant then you can have them hold and move the light around. When I find myself alone then the Manfrotto 420NSB Convertible Boom Stand - 12.8' (4m) is what I use. It doubles as a really tall stand for when you need 12' of height.
If you want to get the computer or electronic screen look like it is on:
If you are using flash, turn up the ISO setting. When I am using a D700 I turn up the ISO to 1600 and that usually drops the flash, etc. enough automatically so that the screen is bright and shiny and the flash does the rest. You will need to move the light sometimes, relative to the item and camera position to avoid obscuring the screen with the light highlight (reflection) on the screen. Come to think of it, I used the same solution with my D70 as well.
If you want shine or reflection of the object on the posterboard:
First, get some glossy posterboard. Most posterboard is glossy enough so this shouldn't be a problem. Then, make sure to get down low relative to the object so that the reflection is extended in the camera view.
Really, with just a few pieces of foamcore and some posterboard, you can have a great setup for excellent ebay pics.