I'm not sure if anything can be done about this now for my phone but I've started noticing that the blue active bar has imprinted itself on my phone. Even when I'm in other applications I can still see a shadow of it. Eeek! Time to cut back on Mumsnet? Is it going to get worse?
Try playing this on repeat on your phone for a few hours: www.youtube.com/watch?v=kt3JxA94ZAI It works on TVs that have images burned in so it should work on your phone too - basically the static gives all your pixels a good work out.