Anti-reflective filter for 11.6 Notebook Computer Screen

My  HP Pavilion DM1-4108AU notebook  computer works well now I have more RAM and Linux running on it. But the 11.6 inch screen is very shiny, making it hard to read in a room with overhead lights and almost impossible to use outdoors. There are anti-reflection add on filters: Fellows and 3M Flat Panel Privacy Filter. The smallest Fellows filter appears to be for a 12.1 inch screen (3m have a 11.6 inch unit), but it looks like the plastic sheet can be cut down to a smaller size. These appear to consist of a sheet of tinted plastic (3M describe theirs as "microlouver privacy technology"), shiny on one side and textured on the other. You place the filter on textured side up if you want to cut down reflections. The plastic also has the effect of blocking viewing from an angle (thus "privacy filter"), but it is not clear to me how that is achieved. These filters are relatively expensive (about $25 for the 11 to 12 inch units) and I have not seen them stocked in Australian stores, although Office Choice offered to order one in for me. There are also anti-glare screen protector which do not claim a privacy function and start at about $5.