I made a thing (and so can you).
Take a look at this slideshow of gifs. It’s pretty basic, but here’s what’s pretty cool: You can plug this gallery into any of your own Tumblr blogs with very little fuss. It’ll grab your most recent photo posts, feed them into this jQuery gallery, and even include the Tumblr iframe for each post so your visitors can like and reblog ‘em.
Want it? Here’s how!
View the source code of that slideshow and copy it. It’ll work as-is for any Tumblr without any changes.
Head to the Customize Theme area and add a new page.
Select Custom Layout, give it a url, decide if you want to display a link (if your theme supports it), and…
Paste the source code in the form and enjoy.
(There’s a TON of stuff to add in future versions of this thing, but also feel free to improve it however you like if you’re into it. Be sure to check out our API Docs if you like to tinker. It’s fun!)