Example 1 (this is over MSN)
you: were u go this time
friend: loo
you: ok did u av 2 tell me that
friend: u asked
you: u could of said 'u dont want 2 no'
friend: oryt wel, i didnt =D
friend: lol
you: lolzol

Example 2:
Person 1: Hi
Person 2: Hey
Person 1: umm..
Person 2: uh.....
Person 1: lolzol

Example 3:
Person 1: I like to pick my nose and then massage the boogers on my anal orifice
Person 2: lolzol

Example 4:
Person 1: I got fired from my job today, got dumped, contracted HIV, lost an eye, got caught masturbating in the elementary school parking lot then shot the cop who tried to arrest me
Person 2: lolzol