Often used when trying to get someones attention.
Can also be used if someone tries to trick you, but you realize something.
"Ey, wanna go to mah place?"
"Ey, you, come here!"
"1337-speak" for "dude" "K3w1 d00d" however, is often used to bescribe those who use such words...
h3y d00d! l37z k!11 sum n00Bs!