Colour barcodes and cellphone

A method of using a barcode on an electronic screen as a game;

• where players move on the foreground rectangles;
• where there are 1 or more human players;
• where there are 0 or more computer players;
• where a player symbol uses non-default foreground colours;
• where there are 0 or more foreground rectangles with desirable items like treasure or food, that players try to reach.

A system of a cellphone networked to an electronic book Reader;

• both interacting with an Automated Teller Machine (ATM) and its camera;
• where the cellphone has a camera;
• where the Reader's screen shows barcodes to be imaged by the ATM camera;
• where the cellphone camera images barcodes on the ATM screen;
• where the cellphone and Reader exchange data;
• where data is transmitted between the cellphone and ATM in full duplex mode via the barcodes.

A method of a barcode encoding an URL and showing a graphic on the barcode's foreground rectangles, with non-default foreground colours;

• where the graphic is a fixed image;
• where the domain of the URL is fixed;
• where other parts of the URL are varied prior to display of the barcode and graphic, to maximise the number of foreground rectangles intersecting the graphic;
• where dummy subdomains and subdirectories are added;
• where the port number is added or removed;
• where dummy (parameter=value) pairs are added;
• where the order of (parameter=value) pairs is varied;
• where the case is varied for some or all of the letters in the URL.

A method of a barcode encoding an HTML form with an action that has an URL of a web server that parses the submitted form;

• where the barcode appears on a screen that shows changing images;
• where a cellphone with a camera decodes the barcode and shows the form in a browser;
• where the user fills in the form;
• where the cellphone submits the form;
• where the web server uses the form to change the display where the barcode appears.