@Jeffro -
Regarding optimising your theme images

I'm not sure what the modern equivalent is but Photoshop used to come with a programme called image ready They discontinued that a while back but the part I used was the image compression which optimises images by stripping out extra info.

The RIOT tool mentioned above by @DB is an image optimiser but doesn't look like it works on a Mac which is what I mostly use. In my view that makes it anything but simple.

Regarding Smushit I have 1 client who has been using it for 2+ years as it is a convenient and easy way for her to manage images on her website.

My first recommendation was that she use Flickr or any number of image projects and link back to them since the original web hosting package had limits to the size of the website as she likes large photos. I still think this is best for most users given that some of them want to display photos at multiple resolution sizes.

Using FTP I pulled back copies of all photos - optimised the ones being used & reloaded them back up to save server space but time consuming and in the end we just bought more space on the server.

The other easy thing to do (if you have a good image programme) is to resize large photos down to more manageable sizes. 1200px x 800px might be a good option for most.

Google Analytics can usually tell what resolution your site users are mostly using so that is a good way to pick a size.

The real dilemma there is that PhotoShop is quite expensive and even the stripped down Elements version that I use is comparatively expensive for the parts I use.

For mac users there is a programme called Acorn image editor looks good - although I haven't tried it myself. There is also a programme called gimp which might work but I couldn't get part the homepage of that to tell anything useful about the programme and my know of geek lingo is pretty good. Certainly my client wouldn't understand any of that gimp stuff so Smushit is still the best option for her.

As for unzipping anything on the server - that is out of the question. I work with FTP & servers everyday and I've forgotten you can even do that.