I wonder if anyone's tried to implement a flash or ajax uploader into 3.x ?

To replace the standard popup style. The 4.x one is not brilliant (imo) and I'm still out on the 5.x one.
Note I'm not on about manually 'force feeding' code from 4 or 5 into 3, more adding something else as a hack/product/plugin to replace the default standard uploader. A simple browse button that allowed multiple files may be enough actually.
Does not (initially) appear *that* difficult to do although I've not really looked into this in any detail yet. There are quite a few choices it seems.