Facebook style image upload with thumbnail generation
I have used Jquery file upload with good results. It does need IE to be in compatibility mode, but worked well for chrome/firefox.
UPDATE. It now claims to support IE 6.0+.
I'll focus on point 4 here. It can be done, but you'll end up using iframes (yeah, I now).They can be 1px small, but you'll need them if you want to create thumbnail previews.A good starting point would be here: http://www.zurb.com/playground/ajax_upload
As for creating the actual preview images (smaller versions) you can use CI's image library.Let me know how it works out.