For now, you can put up a notice like this - if you head into
view/accountview.php, below this:
PHP Code:
$profileForm->add(new Comment("Avatar: ", FALSE));
$profileForm->add(new TextField("avatar", $profile->getAvatar()));
You can add something like:
PHP Code:
$profileForm->add(new Comment("<span style='font-size: 10px'>*Please host your images on a site like <a href='http://tinypic.com/'>TinyPic</a>.</span>"));
These pictures have an id tag of 'avatar' and you can probably resize them with a bit of css in your stylesheet.
#avatar { width: 50px } or something.
It should, in fact, be possible to host these images yourself, but it would require some effort... I hope something like this is included in the next release of Mysidia, though.