It's no longer a secret that when I'm not in an active irssi session and you hilight me, that I get a text message. By popular request, I'm writing up an explanation to it.
1. Get irssi. When you're using it, you'll want to have it in a screen session so you can always stay online. I already wrote a guide about Using irssi with screen and SSH.
Descriptions from irssi.org:
screen-away.pl - set (un)away, if screen is attached/detached
awayproxy.pl - Sets nick away when client discconects from the. irssi-proxy. If away gathers messages targeted to nick and forwards . them to an email address.
They are pretty basic to setup and the comments explain things very well. screen-away.pl is just a drop-in script. awayproxy.pl is one you will want to edit.
3. Sprinkle in some magic. So you have these scripts working and you're getting emails about hilights you receive while away. What!? You don't have an expensive phone/contract to alert you? I don't either.
What I do have is unlimited text messaging. Hurray, we're not doing the magic, someone else is.
Example, if my number is 123-456-7890 and I'm a verizon customer, I would set my email to firstname.lastname@example.org.
It's all incredibly simple, but without going through and doing the research, it's a pain to put together. Have fun with this. :)