I found a nice, smart and clean theme from Nokia N95 Blog. That theme is use on N95 phone but I can run it on my Nokia N73 Music Edition. No worries. It support Nokia that uses Symbian OS s60.
If you want to use this theme, you first need to download the .sis file and upload it to your phone. Don’t worry. You do not need to sign this theme because it is free. After the .sis file has been uploaded, you can use this theme from the Theme menu.
However, if you want a similar theme, you can get at Psiloc Shop. It is called Psiloc Reflect. You can get it at $4.38USD. I don’t think I will pay for a theme unless it is really smart, nice and have custom icons.