Here are some IM shortcuts:
ic: I see
oic: oh I see
lol: laugh out loud
rofl: roll on floor laughing
u: you
r: are
2: to two or too
4: for
dunno: don't know
cuz: 'cause
pleaz: please
gr8t: great
y: why
mai: my
g2g: got to go
brb: be right back
sry:sorry
tt4n:ta ta for now
ttyl: talk to you later
kk:okay
roflmho: roll on floor laughing my head off
anywoo: anyhow
ya: yeah
o:oh
kool: cool
coolz: cool (but it's extra cool)
koolz: cool (it's extra extra cool)
wanna: want to
'bout: about
lil: little
nevr:never
somethin: something
hb:hurry back
ttys:talk to you soon