There are an insane amount of themes to download straight off the net for free. No flashing, no modding, just simply uploading the theme files to your phone then installing them in the file manager on your phone. From then on you can simply select them from the theme list in your settings menu. :D
Just search "K800 themes" on google and you will be inondated with sites.
I have that very same theme as bluetech on my phone!!
P.S This is the website I used as it seems to have loads of fantastic themes!
http://www.myk800.lasyk.net/K800i/Themes/
Enjoy! :D:D




