yeah, thats what I do!!!
Smush.it is an online image optimizing tool which was featured on this blog a couple of months back.
Smush.it optimizes your images so that visitors of your blog have to spend less time waiting for images to download.
WP Smush.it uses the Smush.it api to compress any images uploaded by you automatically. So this practically eliminates the need to visit the site every time you add an image to your post. It’s all automated baby ;o)

The plugin download page says:
Every image you add to a page or post will be automatically run through Smush.it behind the scenes. You don’t have to do anything different.
Posts about WordPress Plugins as of December 10, 2008 | The Lessnau Lounge
December 10th, 2008 at 7:23 pm
[...] rankings, getting a lot of back links is important. There are some habits you can get those links Smush.it plugin for WordPress – Optimized Images – isimplyblog.com 12/10/2008 Smush.it is an online image optimizing tool which was featured on this [...]
John Lessnau
December 10th, 2008 at 7:41 pm
I am using Get The Image on one of my blogs but it is a bear to set up and support is paid only. I am always on the lookout for better wp image handlers and will give yours a try.
Nischal Shetty
December 10th, 2008 at 7:51 pm
@John
The Smush.it plugin for wordpress is very easy to install and use. Just upload the folder containing the plugin files. Go to ‘Plugins’ and activate it.
From here on, you dont have to do anything. The plugin automatically compresses any image that you upload!
John Lessnau
December 10th, 2008 at 8:12 pm
I’ll give it a go and report back on how it works out.
Nischal Shetty
December 11th, 2008 at 1:52 am
@John
yeah that would be great
John Lessanu
December 18th, 2008 at 9:00 pm
I never could get it working. I got a database error on activation.
Tschai
February 20th, 2009 at 8:02 pm
Just installed it and it works flawless.
Although the ‘smushed’ bytes are very lill’, for a gallery-site I have in mind all these bytes together will make a difference.
Thanks for the plugin…
Nischal Shetty
February 21st, 2009 at 1:30 am
@Tschai
Glad it works fine
TheShadow
April 5th, 2011 at 5:00 am
Thanks for this plugin.but is there a way to optimize bulk images which has been uploaded before in one full strech