Is there any etiquette about texting?

If you want to discontinue the "conversation" simply treat it the same way you would when ending a phone call. Say you're busy and you have to go, tell the person you'll talk to them later, and sign off. If they continue to text you, don't feel obligated to respond.

There is always a nice way of letting people know that they are annoying.At first answer their questions and then if you don't have anything else to say , you simply tell that person that you are pretty busy and will get back when you get a chance and you sign out!

Simply text whatever you would say if you were trying to bow out of a boring or monotonous phone conversation.

Just say you have to go do something - finish homework, meet someone for dinner, etc. Obviously choose something that you can't do while you text.

Or you can say your phone is running out of battery.

GOT 2 GO C U L8R

Have a good excuse, i.e. you have to do your homework.