Scratches, like wrinkles are inevitable. If it bothers you, buy one of they myriad cases available.

More good Apps:

"Crosswords" - By 'Standalone Inc.' Great crossword game.

"Units" - FANTASTIC, must have utility. Convert any measure. Time, volume, currency, area, length, speed, energy...wow...

"Wordpress" - For bloggers

"Evernote" - Save (and have transcribed) audio, text, or photos. Take a picture of a whiteboard and it'll be transcribed for you.