I've been trying to add a new avatar, but apparently I can't use .jpg extensions. And I can't really convert those .jpg into .png. Is there any way that .jpg support is added?
Hmm, I'm not aware of jpg images not being allowed. If you upload the file into this thread I will see if I can figure out a solution.
I'm pretty sure you won't like this exact link, because you can't simply download it and convert it. To get what I mean, refresh the page. .-. Spoiler
When you upload a new avatar to EC it is stored here so you can't really use an external service to randomize an avatar upon refreshing. The closest thing you could do is turn all the images you want into a very slow-moving .gif file.
Ah, I can see why it never worked now. Twas an interesting idea, but unfortunately the avatar system is not that sophisticated. If it doesn't detect a single file that doesn't exceed the size limits then it will be completely unresponsive. The best thing to do would be to, as Ethan said, make it a slow .gif file.
The image within the spoiler changes every time the page reloads, which is really cool. I don't think the avatar system can do that.