5800 Confusion

Hey people, I seriously need help here... How do you people differentiate ur 5800 from your peers besides those charms which you can hang...?

Both my mum's and younger brother's operator contract were due for upgrading and they've just gotten their own 5800... And for the past 2 mornings we have difficulty differentiating the phones since none of us is keen on having things hanging from our phones... please gimme some suggestions man... i've already changed my wallpaper so that i dun bring the wrong phone to work in the midst of hurry...