i've done this

RewriteRule ^([A-Za-z0-9-]+)/?$ profile.php?user=$1 [L]

to make

www.example.com/profile.php?user=testing

into

www.example.com/testing

What i'd like to do is change..

www.example.com/profile.php?user=testing

into

www.example.com/user=testing

What is the RewriteRule to accomplish this? Also if i used $_GET with the second clean url would it still work?

Try this.

RewriteEngine On
RewriteRule ^user=([^=]*)$ /profile.php?user=$1 [L]
commented: nice +13

Add the . within the square brackets.