OK, I think it worked. Here's the basics:
1) Set up an account somewhere that allows you to post your photos and then display them on other sites. Sometime soon that'll be Neighborhood Link, but in the meantime I recommend Flickr. It's free for personal use, it's aimed at photographers rather than porn, and it works very well.
2) Upload your photos to Flickr, or wherever you've chosen. Make sure to set permissions on the photo so it's viewable by "everyone" rather than "only you" or "friends and family only."
3) Open two browser windows - one for NL and one for the photo. Get to the post/reply window on NL, and have the photo, in the size you want, in the other. When you want to insert the photo, just use your mouse to drag it from the other browser window into your post.
4) If you're using Flickr, their terms of service say that anytime you display a photo you've got hosted on flickr, you'll include a link back to the image on their site. So, click once on the image in your post, then click on the link icon: 
and put the URL for the Flickr page in the "link URL" box. The URL should be the one for the page with your image on it, not the image itself - the URL will look like "http://www.flickr.com/[...]/2443401246/" rather than "http://farm3.static.flickr.com/[...]b1_m.jpg.
That's a lot of words but it's actually pretty simple. I think this might be a good candidate for a little instructional video, like the one in our FAQ that shows how to add a picture to your profile. But give it a try in the meantime and let me know if you run into problems.
The most important thing to remember about this process of dragging a photo into the discussion post editor is... what you're dragging is a pointer to where the photo really is... if you dragged it from Flickr, then when people view your post they're loading the image from Flickr. If you just drag it from your hard drive, or from your Hotmail account, or such... nobody else has access to that so nobody but you will be able to see the image! So you first have to find somewhere like Flickr that will let everyone see it.
