I actually use texting to raise IL. For example, a chick texts me and I won't respond for five or six hours. If it's unimportant, sometimes I don't respond at all.
It's a good way to show a chick that you have other things going on in your life.
I got flaked on last week through a text. A girl was supposed to come out with me for some drinks, but she sent a text about six hours before saying she had to stay home and study for her grad school exams. I didn't respond, and sure enough the next day I got an e-mail from her. She was frantically wondering if I had gotten the text or if I was mad at her about not being able to come out with me. I just said that I forgot to respond, and that her canceling wasn't a big deal because I had other plans anyway.
I think the key with text messages is to not overuse them or rely on them too much. It's also good not to respond immediately.