Here's a general concept....
Texting is to your cell phone as
Email is to your computer.
A clip from the web ....
The "Short Message Service" is a feature available in most modern digital phones, that lets users receive and send short text messages (from 150 to 160 characters) to other cell phones. In order to send and receive SMS text messages, phone users usually have to pay a monthly fee to their service provider or a small fee for each text message. Some companies even offer SMS free of charge. Text Messages can also be sent from a cellular service provider's web page or by visiting some web sites that offer to send text messages free of charge. On Nokia phones, users can receive new ringing tones or replacement background logos in an SMS text message after placing an order on a specialized web site.
More detailed and technical explanation here....
http://www.wisegeek.com/what-is-sms.htm
To text someone, you would normally go into your phone's Messaging menu and click something like "Create Message". It would ask for the recipient, which is usually someone else's phone number (incl area code). Then you also get a text area to type the content of your message. This is limited to about 140-160 chars. When you hit "Send" the message travels over the cellular network and arrives at the other person's phone, which they can read. Just like in email, they can delete it, keep it forever, or reply back, or forward it.
Most people just go into their Message Inbox and find an old message that they had from someone and just hit Reply instead of creating a new one. It is usually faster.
From phone to phone, text messages are often almost instantaneous. But sometimes there may be a delay, so urgent and important info should not be solely relied upon in a text message.
Many phones will also let you send text messages to normal email accounts and vice versa. Instead of specifying a phone number as the recipient, you just put in an email address. It first goes to your phone carrier, and their system translates it into an email and sends it out. When it comes back the other way, folks can send a short message to your phone by knowing the email address your phone carrier has for your cell phone. Verizon is usually like this: xxxxxxxxxx@vtext.com (where the x's are your phone number). Alltel's look like this, I think: xxxxxxxxxx@message.alltel.com. Any messages to those addresses go to the carrier company and their computers change them into SMS/text messages and forward them on to your phone. If the message is too long, it is often truncated or split up into multiple messages. For a list of the email addresses for other wireless carriers, see SMSCarrierEmails.
I love sending my email account reminders via text messages. Later, when I'm at my email on a computer, I see all the texts I have sent myself. I text myself all the time: "Ask off for vacation next friday" or "Search Google for pricing on 9mm pistols", etc.
I like text messages for when you want to ask someone a question, and want to give them time to think, instead of wasting your cell minutes, or being put on the spot with a phone call.
Or if my wife calls me while she's doing errands and needs the location and phone number of a particular store. I can use my email to send her phone a text message with all the info on it. She can just look at the phone and reference the text any time she wants instead of me reading it to her and her having to write it down.
Or if I am somewhere that requires quiet, I can set my phone to vibrate and text to my heart's content, when a voice call would be out of the question.
Or if a friend says, "Come over after work on Friday and we'll grill out. Just bring some rolls and some drinks." I'll send a message to my main email address that reminds me what I have committed.
There are also some services out there that will send you text messages when special things happen. For instance, I get a text message every time a college basketball game ends. The message tells me the teams and the final score. That is commonly referred to as an "alert." Often your carrier offers this kind of service as well. Perhaps a "Joke of the Day" or a stock market quote would be delivered to your phone at intervals that you set.
There are also web sites that have ToDo* lists that you manage online, and they offer SMS interactivity. You can create a todo item right from your cell phone, or get a list of items you have in the "Home" category right before you begin your chores on Saturday. All this you can do from your phone. Sites: www.rememberthemilk.com and www.hiveminder.com are some popular ones.
Now some tv shows, like American Idol, let you vote with text messages. They have a short number (called a "shortcode") that you type into the Recipients box that they have registered for themselves. They will give you instructions on what text to send to that number to make your vote.
Google also has reserved 466453 which are the numbers that spell G-O-O-G-L-E. Their computers are listening for any messages sent to that number, and when one with a special command comes through, Google's computers act on it. If you send that above number the following: "weather Raleigh,NC" (without the quotes), then Google knows that you want a weather report for Raleigh. So it replies back with a a short message telling you what the weather will be like.
More info\:
http://www.google.com/sms
Google Calendar also has special commands that you can send to it. It has a different number: 48368. It spells G-V-E-N-T and you can send things to it, like in my previous post, that cause it to interact with your Google Calendar. You have to have a Google Calendar already established. Also, you must go into your calendar settings and register your phone with it, so that it can match up your cell phone with your calendar.
Google Articles\:
Check your calendar via SMS
http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=37228
Create an event via SMS
http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=37529
Sometimes in remote areas, text messages can get through when voice calls cannot. They take up so little bandwidth, that if the phone is able to get a signal for an instant, often it can send the text message, when it would have already dropped a voice call.
If the recipient has their cell phone off, they may never get the message. The carriers sometimes don't keep the messages in queue waiting for the cellular customer to turn their phone back on.