Where to get a free download for cellphone wallpapers?

Recently I saw very beautiful wallpaper at one of my friend’s mobile phone. It was real looking wildlife wallpaper and it really looked very beautiful. But before I could ask him to send it to my phone via Bluetooth he left the party. Now I searched for similar wallpaper on the internet and even found one but it asked for money for its download. Can anyone tell me with a place where I can download this wallpaper for free? I don't want to spend money on it downloading it I want to download it for free, can anyone tell me a place where I can do so?