Rather than creating a single image dynamically (with the GD module or whatever), an easier, more CPU friendly option would be to have separate images for A-Z, a-z and 0-9, and place a selection of them side by side to create a unique word.
Code could be reused from any number of open source counter scripts, and shouldn't require any extra modules.
Just make sure that you use a "*" character or similar in the ALT tags.
Code could be reused from any number of open source counter scripts, and shouldn't require any extra modules.
Just make sure that you use a "*" character or similar in the ALT tags.