Each of your Ringio users can record a personal greeting for their voicemail box.  Here's how to record your greeting from your phone.

Step 1. Log into the Ringio application.

Step 2. Click on your account button ("Jon" in this example) to the left of Taking Calls in the top right corner. 

Step 3.  Click on Personal Voicemail Greeting button.

A dialogue box will give you the option to use your own voice recording.

Step 4.  Click Call me to record my voice.  Ringio will call your phone.  Answer when it rings and record your message (press the # key to finish).