How to Access Verizon SMS Messages

1. Press the 'Menu' key on your Verizon phone. The phone should be on the standby screen.
2. Select 'Messaging' or 'Messages' and highlight the SMS message you want to review. Press 'OK.'
3. View the entire message by scrolling through it using the arrow keys.
4. Press the 'Back' key to select another message to view.

How to Set up a Cingular SMS Message Center Number

1. Access the main menu of your phone and choose 'Messaging.'
2. Go to 'Options'/'Settings.'
3. Go to 'Advanced.'
4. Verify that the message center is: +12099042010 (West Coast) or +17045020600 (East Coast).
5. Press 'OK' to save the settings.

How to Send an MMS Message to a Cell Phone

1. Find a site that will enable you to send MMS messages free of charge. A few that you can use are Text4free, SeaSMS and SMSFree4All. All of these sites will allow you to send free SMS and MMS messages, as of 2010.
2. Go to the site and type in the phone number to which you wish to send your MMS. Select the country and the cell phone service provider (note that not all of these site allow you to send messages internationally).
3. Type in the message that you wish to send. It must be 140 characters or less.
4. Click on 'Choose' and select the file that you wish to include in the MMS from your computer. This can be a photo, sound clip or short video. The file must be 500 kilobytes or less. Enter the captcha code if required and click 'Send.'

How to Send an International SMS Text

1. Determine if your carrier provides text-message service to the country and carrier of the intended recipient.
2. Create the text message. Standard text-message limitations, including length and content, apply to international messages
3. Enter the international access code in the recipient number area. It is possible to use either '011' or the plus (+) symbol.
4. Enter the recipient's full mobile number, including country code. Press 'Send' to complete the action.

How to Make an SMS Without Showing Your Number

1. Access an SMS messaging website of your choice. Text 4 Free, Text'Em and Text For Free, are examples of websites that do not require that you disclose your cell phone number.
2. Read the terms of the service agreement.
3. Fill out the form on the website. It will include the recipient's cell phone number, cell phone provider, subject and the text message.
4. Verify that you typed the information correctly and click 'Send.' A confirmation will load confirming the SMS message was sent.

How to Send Receive SMS Online for Free

1. Go to a website that offers free text messaging service such as 411SMS, Chikka or TextEm.
2. Register your mobile number on the site that you choose. You will also need to provide a user name, password and email address. After you've completed the registration process, you will receive an email. Click on the link in the email to confirm your registration and log in to the website. 
3. Compose your text message. You are limited to 160 characters. Once you have composed your message, type the recipient's cell phone number into the appropriate field.
4. Enter the verification code and click 'Send.' The service will automatically send the message to your recipient. When the recipient replies to the text message, a notification will appear in a popup window on your desktop. Click on it to read the message. 

Alternatives to a Second Phone Line

T-Mobile's HotSpot @t Home
If your issue with using your cell phone as a second phone is the fear of racking up too many minutes, T-Mobile's HotSpot @Home service might work for you. It works with certain cell phones that are Wi-Fi enabled. When you're out, you use it as a regular cell phone, but when you're home, or within range of any T-Mobile hotspot, your calls automatically switch to Wi-Fi, saving you cell phone plan minutes.
VoIP Phone Service
Many VoIP phone services charge less than the phone company charges for a second phone. Installation is also either free or low cost, and you can usually do it yourself. No wiring is required beyond plugging in another device between your broadband modem and your computer. Vonage is the best-known service that allows you to make regular calls to anyone with any kind of phone number, and to use your regular phone. Other services exist, and your cable TV provider may have a similar service. Monthly fees of between $20 and $35 apply, as of 2009, giving you unlimited local and long distance calling and low-cost calls to many other countries as well.
VoIP via Computer
Services such as Skype are often free if you call only people who are also members of the same service. Typically, you need to sign up for a user account and download software, and your computer needs a microphone and speaker, or you need a headset with a built-in microphone. Some of these services let you pay a small fee, usually a yearly fee of $10 to $30, to purchase an account with the ability to make and receive calls from people with regular phone numbers, but you usually still have to do it using your computer, or purchase a special phone device.
Google Talk and Other Instant Messaging Apps
Online chatting or instant messaging is a way to communicate in real time without a phone. But many providers of IM, including GoogleTalk, have a voice option. It works similarly to the way Skype works, letting you talk to another member of the same service using your computer hardware and the Internet connection. These services are usually free.
Google Voice
Google Voice is not a second phone line but a way to manage your various phone numbers. Sign up for Google Voice and obtain a phone number. Give that number to your friends and family instead of your other numbers, and you can configure how it works. Specify that when family members call, it rings at all of your numbers. But when those annoying telemarketers call, it will go straight to voicemail. Change which phone it forwards to depending on your circumstances. Check voicemail from anywhere on the Internet, and forward messages to others. Google Voice is currently available by invitation only, as of mid-year 2009.
Internet Call Waiting
If you have dial-up Internet and you don't want to miss calls that come in while you're connected to the Web, you can get a service such as Phone Tray, which tells you who is calling and gives you the opportunity to answer the call. PhoneTray has a free version, or you can pay a one-time fee of less than $20 for the full version as of 2009.