If you want to set it at 480p then uncheck 1080i, 1080p, and 720p then save your changes. Go back to your browser and you will notice a big difference. you can also adjust more settings to the screen size and text size within the browser. it looks much better especially you have an HDTV. 480p will cause the text size to be even bigger!
I now have mine set at 720p. If you have really bad eyes then set it at 480p. Set it back to 1080p or 1080i if you're playing games or watching a blu-ray movie. 720p is nice for playing mpg videos and browsing the internet.
The PS3 controller is cool to use when switching between pages. So get familiar with the buttons. The start, select, L1, L2, L3, R1, and R2 buttons are very useful.
Hope that helps.