One of the tasks I was recently given at my job involved examining issues with a browser-based batch file upload component. The component that was being used, iBULC, required a separate installation of proprietary software on the client-side, had a rather clunky browser interface, and proved difficult to troubleshot. Rather than expending effort to get iBULC to work properly, I went in search of a new solution. That new solution is SWFUpload.
Outside of those issues, I was quite happy with the results. I was able to put the new solution together within an afternoon, it uses the native OS interface for multiple file selection, and it allows me to respond to the events that occur in the file upload process however might be necessary. I’d definitely recommend that you check SWFUpload out if you’re in need of a similar solution.