Add photos to upload applet during transfer?

Especially on a slow link, it drives me nuts not being able to drag/drop files onto the applet while it's uploading.

I'm browsing a huge tree of my old photos, and when I find something I want to toss into my gallery, I drop it in the applet and hit upload. If, during that upload, I encounter more good stuff, I have to sit on my hands until the upload is done. (or cancel the transfer, add the files, and start it again.)

Any plans to separate the "drop stuff here" thread from the upload thread?