Question: I have an existing album. I'd like to upload several more images directly into that album. Is there an easy way of doing that?

The only controls I see are:

* On the album page, "Add images", this only supports existing images
* On the upload page, I can add to a gallery or create a new album, but I cannot add to an existing album.

Am I missing something?

Answer: 
I was wondering the same thing! Here we go:

1. Click the "images" link in the top right nav.
	* URL path should become `/all/`.
	* "Add to album" dropdown should appear on the right.
2. Pick an album in the dropdown.
3. Upload image via drag-and-drop or using the "Computer" or "Web" buttons on the right.

Good luck!
I just figured it out. Imgur won't let you add images to a public album. 

1. Edit the album, make it private, save.
2. Edit the album, add the image, save.
3. Edit the album, make it public, save.

The app will let you do it in one step but it won't actually work unless it's separate saves.