You probably already know about Yahoo Smush.it tool ! It reduces images file size but keeps the images quality (for real, it really does a good job). WP Smush-it is a WordPress plugin that automatically smush your images. It's incredibly helpful if you are too lazy to optimize all your images for the web like me. :) You can also use it to smush your existing images (but you will have to do it one by one).
The only problem I had with this plugin is that it didn't work for me because my upload folder wasn't in the wp-content directory. I had to tweak it a bit to make it work (I didn't want to wait for the next upgrade). Here is what I did:
Look for line 127
// check that the file is within the WP_CONTENT_DIR
Add this right after it :
$upload_dir = wp_upload_dir();
$wp_upload_dir = $upload_dir['basedir'];
$wp_upload_url = $upload_dir['baseurl'];
Replace WP_CONTENT_DIR by $wp_upload_dir
And WP_CONTENT_URL by $wp_upload_url
in lines 128, 129, and 135.
Voilà, thank you for this wonderful plugin for all Page Speed/YSlow freaks like me ! :D

on March 4, 2011
at 05:21 AM
Does this work even if images are not in media library? My images in are in a subdomain but not in media library
on June 23, 2011
at 01:19 PM
I think it only works for images in the media library :/