I am a FireFox user, but this add on to Chrome made me install it, just to use it!
It is called Mighty Text, and when it sync's up to the Android app running on your cell phone, it lets you text (send and receive ) message people via a little box that pop's up on you browser (look at photo attached).
The way it works is your cell phone will receive a text, and it will send to the Chrome Mighty Text if it is up, you will then reply via your browser, and the text is sent to your phone, and then to that person. I have had very little delay with it, and it is VERY useful for when I am in class, and I dont want to be rude by pulling my phone out to text, and the same for at work. It will also sync with your Google contacts, which is very nice.
I suggest everyone to try it out. It is worth it.
Oh yeah, then App for both Android and Chrome is free.
Link -
http://mightytext.net/