BuddyPress.org

1) i would like help finding out hw i could get the specific username of a user..
i want it to be that when i am on a profile page of a user with a certain username then it will show something..sort of like an if username==’myname’ then display ‘this’

2) i also want it to reflect in the activity stream, with all activity from a specific username or user id, it will also show some text..for example whenever ‘username’ posts an activity update:
username posted an activity update : blah blah blah,
“my custom text i want to show for this username comes below it”

could someone help me with a function to do this as i have no idea to go abt it?