Wanted to change the default TouchWiz Launcher on your Samsugn Galaxy S2 (sgs2)? But do not want to make all those rooting stuff? Have no fear. There are several launcher apps that can replace the stock launcher on SGS2. My favorite is the LauncherPro. There is a free version. Checkout this video particularly the cube transition effect and the 3D app drawer effect.
Update: Since my SGS2 was upgraded to ICS 4.0.3, the Launcher Pro kept crashing. Found out there is not much development of it anymore. I changed to Go Launcher EX that I find better than LauncherPro because it has lots of homescreen transition effects to choose from. My favorite is the Windmill and Cube inside.