Giving in to MySpace & Facebook?

That's a great idea. If they know anything about html they can manipulate the code and take the link off though.
In our new pricing we offer web sized images to put on social networking sites. They will have a very small bit of text at the bottom with our website. I find no one really minds that at all. The link would be awesome though. However, with a lot of those sites you just upload your pictures into the albums, so that would negate the html thing anyway...

With the right mix of PHP, HTML, and CSS it would also be possible to have a banner across the bottom of an image with your company name or web link that didn't show up on your site but is there if they save the image or link directly to it.  It would be really easy to crop out though.  Still not ideal I guess.  

The coding for this could get a little hinky, but it should also be possible to write a script that actually serves the image instead of directly linking to the JPG.  Then, before displaying the image look at the page that's referring to the image and make sure there's a link.  No link, display another image.  That has the potential to make your server get really busy though if an image is linked from a popular page.  Could always be cached I suppose.  

Just throwing out ideas.  Don't know how workable they would be in practice

What it comes down to though is that the images are going to be out there whether you want them to be or not.  They can either post a crappy scan from a pebbled print or can post an image you've sized so that it looks good on the web. 

I like your idea, Ryan. I'm wondering if myspace and facebook's photo album viewers would be able to support links like that.

Wouldn't it be nice if there was a sure way to protect your images online? People are always going to find ways though. Although, I would love to have a code that gives them a completely different picture if they take a screen shot. Something like a big flag waving that says "Nice Try" on it. Hahaha