So far I have made following contributions for making world a better place:

• I have cleaned one very dirty bathroom (as mentioned before).
• I have proved to one person, that even though the trash is laying everywhere on the streets, he can change something, when NOT throwing his empty plastic bottle there additionally.
• I have taught one guy from dormitory's cleaning staff, how to clean the carpet from the dust (without vacuum cleaner).
• I have got used to go to bed late(r) and wake up earli(er)
  (I know, it is a small step for the humankind but big step for me ;)