Knowing who sent you a text message before even looking at your phone is extremely convenient, especially if you are the type who receives many SMS messages daily. One way to know who is on the other end of that SMS you just received, is to customize the text alert, based on a contact, on your iPhone. It is a simple process to set up, but one that is easy to miss if you aren't paying attention.
While this capability has been around for those in the jailbreak community from early on, it's a fairly new feature having been introduced in iOS 4.2.
The first step to setting up a custom text alert for a contact is to decide which contact(s) you want to have a unique sound. After you have thought about it and come to a decision, open up Contacts on your iPhone and select that contact.
You should now be viewing the contact card of the individual you had selected. Tap on Edit.
Scroll down until you see the "text tone" field, it should read Default. Tap on it. Yes, we realize there is a Vibration setting in this screenshot; it's part of iOS 5. We have already covered how it works; you can find the post.
Here you will be presented with a list of all the Alert Tones. Here you can pick a sound that is different from your default text tone.
When iOS 5 is released, users will also be presented with a Ring Tones list, allowing them to set custom made or paid ringtones as text alerts. (It's about time, right?)
Press Save when you have chosen a new tone.
This time, when you view the contact card, you should see the a Text Tone field, as well as the sound that is set for that contact, as seen above.
One more tidbit regarding iOS 5. With iMessage coming to all iOS devices, including the iPad, you will be able to set custom text (iMessage) alerts on the iPad using the same method we just covered.
Now you can customize your alerts for all of your favorite, or possibly even your least favorite contacts.