yes, php does have support for non-database systems like this.
I use a flat text file for storing my usernames, passwords, and some basic information. This method is pretty good for a small number of users, but another above, what, 1000?, and you might want to consider upgrading to a real database.
Anyway, I posted the code in this thread this morning (
http://www.programmingtalk.com/showthread.php?t=15558 ) but incase you dont' feel like going there, here it is again.
$filename = of course, the filename
$userline = creates the line that will be stored. Remember to include \r\n to start a new line at the end of the current.
$handle = opens the connection to the file. If the file doesn't exist, then it's created (provided you have permissions)
fwrite = adds the line
fclose = closes the connection
That code above createst the file that will store the username and password. I used the "|" character to seperate fields, but you can use anything unique. Then, it's a matter of reading the file. I use md5 encryption to protect the passwords and works pretty well.