First suggestion: I read in another thread that the focus of this plugin is just to publish to the activity stream and not to make a gallery for each user. I can understand that, but there is still a way that could at least make this plugin a little more awesome without having to do all that work. The activity stream has a drop down filter to isolate certain kinds of posts. I have seen other plugins add an option in the filter to show only those types of posts. That could work great with Activity Plus - have filters for photo posts so that you can view just the photos that have been posted in the activity stream (or videos, links, etc). Please please?
Next suggestion: Allowing videos to be uploaded directly to the domain instead of only being able to add a link. I understand that different hosts have different upload restrictions, so make it an option to change the max upload size, with the default being low enough to satisfy most hosts.
Last suggestion: Improve the icons used to post to the activity stream. They are too big and stick out really badly.
Thanks for your consideration.