stripping all non alpha-numeric characters from string

[bcamp1973]

ok, i want to strip all instances of "\r\n", "\r", "\n","\t" and non-alpha numeric characters from a string. in my searching through the PHP manual there seems to be a lot of options...such as str_replace, preg_replace(), ereg_replace() etc. i need something that's fast an efficient and i'm guessing i'll have to use regex of some form but it's not something i'm very knowledgable of.  any suggestions?

[Caesar]

Take the reverse approach, only match those characters you want to retrieve. ;-)

[obsidian]

i like this approach:
[code]
<?php
$String = preg_replace('|[^a-z0-9]|i', '', $String);
echo $String;
?>
[/code]