Is this my daughter sending in this question? Hmmm.... actually, Facebook chat is pretty cool because unlike a lot of instant messenger services, it supports a bunch of cool things you can do, including underlining words and even putting words in bold, as well as the emoticons that you're talking about.

Unfortunately, Facebook has also left it as a bit of a guessing game too. If you can even find the help area in Facebook (hint: it's on the Settings menu) you'll learn that they show about a half-dozen of the most obvious, like :-), and say "but we're always adding more so experiment and try things out". Not so helpful if you want to just _know_ how to do it (and that notation there of the "_" before and after a word? In Facebook chat that'd make the word underlined.

Here's what I have been able to figure out, though I had to make up a few of the names...

:-*	kiss
^_^	kiki
-_-	squint
O.o	confused
>:O	upset
<3	heart
:v	Pacman
:|]	robot
:)	smiley / happy
:(	sad
:P	tongue stuck out
:D	grin
:O	gasp
;)	wink
8)	glasses
B)	sunglasses
:3	cute
>:(	grumpy/mad
:/	unsure
:'(	crying
8-|	cool but unsure
<(")	penguin
3:)	devil
O:)	angel
:putnam:	(Facebook engineer Chris Putnam)
(^^^)	shark!

In addition to all of those, if you start and end a word or phrase with the "_" symbol, _like this_, you'll end up with it underlined and if you surround a word or phrase with "*" sort of *like this* then you'll end up with bolder text. I haven't yet figured out how to italicize things, and I'm sure that there are more emoticons lurking in Facebook chat, but I haven't found 'em yet. If you have, do share here in the comments.

Hope that's helpful!

And while we're at it, you should know that I have quite a bit of Facebook help here on the site and that I also have an Ask Dave Taylor Facebook Fan Page that I invite you to join.