Je ne peux pas répondre à cette question.

Well, originally "x3" or ":3" is used in manga to represent a cat, or someone cute, "kawaii" in Japanese.
But some use "x3" as a heart... So it all depends on the context in which it is used!
For example, if someone says to you, "I love you x3," it's logically a heart.
But if they say, "I saw a cat" followed by the smiley "x3" or ":3," it can represent the cat like in the manga, or say that it was cute...
In any case, for me, a heart is <3 and not x3. But everyone has their own point of view! ;)
I hope I was able to help, and as mentioned earlier, review the context in which it was used and deduce its meaning! :)

To respond to Coline, I know the smiley :p which represents a face sticking out its tongue, and I think that =p means the same thing but with just the expression of the eyes changing.

X3 or :3 comes from the character Izumi Konata of Lucky Star, it's the typical mimic.

http://img187.imageshack.us/img187/5973/luckystarbr9.jpg

there you go, there you go

x3 > Well, I thought it was some kind of cow ^^, I've always found the 3 a bit like a cow's muzzle and I don't know why. After all, a heart can work to facilitate texts... We'll see... But with the many given responses, it would rather be a heart ^^*

^^ > well, it's someone who's laughing. We can see this smiley better like this: ^_^.
^^ = The eyes
_ = the mouth.
Some write it like this: ^^, (, = side mouth)
There's also this one: ^^'. It means: Oh yeah, that's right, while laughing a bit.. ( ' = sweat drop)

xD > You all understood when we tilt our head to the left, we see dead laughing eyes ( X ) and a big smile ( D )

o_O > A little eye ( o ), the mouth ( _ ) and a big eye ^^ ( O )
There are several ways to see this pattern...

Then, of course, there are plenty of smileys:
x) > Like xD, except it has a little smile ^^.
=) > Smile
=D > Big smile
;) > Winking smile
;D > Winking big smile
=0 > Open mouth ^^
..etc

Oh really?? Does it mean times 3?? I rather see a face of someone who is frowning (or rather their eyebrows) represented by the x and the 3, it's a mouth, like we can see drawn in certain manga. We can also put an apostrophe behind the smiley x3', the ' represents a droplet of saliva, to say that the kiss is drooly.. lol ^^
Well, I might be talking nonsense :/

Damn! You're really not skilled. Even after 4 pages, you haven't figured it out...

The "x" is the eyes, like in "xD" and the "3" is the mouth. It's like a hamster face. x3

There's also :3 or ;3 for example. It's very cute. ;D

x3 = a heart, it's like "<3".

You just have to look in the opposite direction..

Nonsense!
This smiley is Japanese; the "3" is a mouth for "Neko" [Cat] and the "X" represents the eyes, which gives x3 a "neko" =)

I haven't read the discussions until the end, but I hope to shed some light for you a bit:
- The smiley ":X" is actually a little character (the colons form the eyes) who has his mouth sewn shut; for example, he says something he shouldn’t have said...

- The smiley --' which is the same as -_-' is a bored character.

- :p is the same as =p, it's a character sticking out his tongue.

- x3 doesn't mean "I love you three times" ^^ but it's also a character; the meaning is complicated, the "X" represents the shape of the eyes, we can see this eye shape in some manga.. §

- "JTM" means "I love you" but it's important to know that a "Je t'aime" is much better than a simple JTM... just like "JTD" means "I adore you."

The famous TMTC or TMTS means "You know yourself" for example, after a secret or a "crazy thing" with someone, we can write this.

There you go, if you have any other questions.

:'( : crying
:') : laughing
oO : OH!
actually, most emoticons can be understood by turning them 90 degrees,
for example this one: :) if we turn it, the two dots become eyes and the parenthesis makes the mouth.
the <3, if we turn it, it makes a heart.

Sometimes when I don't understand an emoticon like :O I mimic it myself with my head, using my fists for the eyes and the O for the mouth... the same goes for xD, if we do it with our head, we understand what it means...
*it's complicating things for young people now.
last one for the road x)

Oh là là, vousvous éloignez pour rien. Pour une grande majorité de smileys, il suffit simplement de pencher la tête à droite ou à gauche pour voir une tête représentant quelconque sentiment (joie, étonnement, etc.). Après, pour les abréviations comme jtm ou encore jtdr, si vraiment personne ne vous explique ce que cela signifie, ouvrez un autre sujet que "que représente le smiley..." (dans lequel nous sommes, je vous le rappelle) car avec tous vos éloignements, on commence à ne plus rien y comprendre.

The " x3 " means a heart.

It's a heart like <3 ... x3
There you go =)

In my opinion, it's to make a face, yeah XD the X3 makes a kind of mixed smile.

In fact, <3 represents a heart and some people (especially on phones) who are feeling "lazy" to find the "<" just replace it with an "x," which gives x3
In short, <3 = x3

x3 --> Lean your head to the right! It's a heart..

x3 is like <3 it makes a heart

Heart simply!!

the smiley x3 is a heart!! It's like <3!!