According to Android Legend you can:
Ubuntu Touch is a touch-friendly interface based on the desktop Unity
interface. It is based on Qt and QML and various software frameworks
originally developed for Maemo and MeeGo such as oFono as telephony
stack, accounts-sso for single sign-on, and Maliit for input.
Utilizing libhybris the system can often be used with Linux kernels
used in Android, which makes it easily ported to most recent Android
Now developers have ported this Ubuntu Touch for your own Samsung
Galaxy S2. So if you are bored of using Android, you can definitely go
for it. All you have to do is just follow the simple procedure given
below to get Ubuntu Touch running on tour Galaxy S2.