It is fun to tweak the android OS to get what you want and make the customization. I’m using Android 2.3.7 AmericanDroid NAND HD2 CM7 which has provided the lockscreen wallpapers tweak in it. You may not know it but today i would like to let you know that. Yes, you can change your lock screen wallpaper without changing your OS wallpaper. Cool. If you are using normal Android [not CM7 version], you will not see this tweak. However, there was a post from Xda to teach how to setup lockscreen customisation in normal android os. See the link after the break.
For CM7 Android
1. Goto Settings
2. Goto CyanogenMod Settings
3. Goto LockScreen
4. Goto Style options
5. Goto Choose background
6. Select your pictures and scale it.
7. Click Save then you will see your selected wallpaper appear on lockscreen.
For Normal Android
Follow instruction on thread below:
I tested it on the CM7 ROM but seems it doesn’t work. Please take note you need to download Metamorph to try out.