The first available option in an automatic title configuration is to create the title and keep the title field hidden from your user so they don't even have to see it. This option can be configured by doing the following - please note that a custom content type is used in this example:
Go to Admin menu > Content management > Content types > Edit content type of your choice.
Once on the Edit screen for your custom content type, click on the Automatic title generation fieldset to open it.
Check the Automatically generate the title and hide the field option.
The next thing to do is to add some token values, which are kind of like data placeholders. A token value tells the system to find the specified data in the form you're on and to put that data where the token indicates. Tokens are found in the Replacement patterns fieldset. Click on this fieldset and do not be alarmed when when it opens, there is a lot of stuff in there that can be confusing to someone who is new to token use.
Scroll down the list until you find the name(s) of the field(s) you want to use.
Once you have located the fields, copy the token value, including the brackets, and paste it into the Pattern for this title field. If you use multiple fields, put a space between each token.
Once you are finished adding the token values you want, click the Save content type button at the bottom of the page.
Now, when you go to create this particular type of content, you will see no title field whatsoever. In this particular example, the title will be created by the combination of the First Name and Last Name fields.
This option has both benefits and drawbacks. It does completely hide the field and keeps the user from accidentally entering anything in it, but if there happens to be a typo made in one of the fields used to construct the title, the only way to correct the issue is to unhide the field, which requires the intervention of a user who is permitted to configure this setting, which, in the OSU Drupal 6 installation default, would be an advanced author or administrator.