Hey this is my first tab.  It's a beautiful song and like all Sean Kingston songs
(and most hip-hop/r&b songs in general) it only needs 4 chords to play on guitar, 
just repeat them throughout the song.

The chords are:
F# (bar it or just play it on the first 3 strings)
D (xx0232@1)name="chord_x02220@1">A
E (022100@1)
CHORUS:
F# (244322@1)            D (xx0232@1)            AShawty's (x02220@1)like a melody in my head
                  EThat (022100@1)I can't keep out
Got me singin' like
F# (244322@1)         DNa (xx0232@1)na na na everyday
              A (x02220@1)           EIt's (022100@1)like my iPod stuck on replay

F# (244322@1)                DRemember (xx0232@1)the first time we met
        A (x02220@1)                EYou (022100@1)was at the mall wit yo friend
I was scared to approach ya
But then you came closer
Hopin' you would give me a chance

Who would have ever knew
That we would ever be more than friends
We're real worldwide, breakin all the rules
She like a song played again and again

That girl, like somethin off a poster
That girl, is a dime they say
That girl, is a gun to my holster
She's runnin through my mind all day, ay

Chorus X2  and the rest of the song
just keep playing those 4 chords.