Image Uploader. Different Sizes w/ single upload?

I want the ability to upload a single full-size image, but have it display at a specific scaled-down width. When someone clicks on the image, it will link to the full-size image.

In other words, I want the ability to generate and display two different sizes of the same full-size image.

Here’s an example of what I want…

https://eric-nord.com/?p=6

Unfortunately, to accomplish this, I uploaded two separate images (medium and full sizes) and then manually changed the html. The problem with that is that it will add a lot of work when I upload hundreds of images.

Any suggestions? Any plugins or hacks that might work?

Thanks!!