I've used SWFUpload. The trick is avoiding "File Upload Not Allowed Exception"

Notes/Domino 8 Forum

Subject:

I used SWFUpload.org's code.

It was a bit of JavaScript, and it's impossible if you don't know that Domino by default doesn't allow submitted fields that aren't on the receiving form, and since a File Upload Control actually has a field name behind the scenes, like "%%File.uglyuglyuglyugly12345", most people miss it completely and end up getting errors in their log that look like

HTTP Web Server: File Upload Not Allowed Exception

The field checking is a good thing. You can disable it with an Notes.ini setting of DominoDisableFileUploadChecks=1 but that has security implications across your server. Instead put a 'real' file upload control in with an ID of FileUploadControl, then passed that ugly "field name" to SWFUpload with
swfuploadsettings.file_post_name = document.getElementById('FileUploadControl').name

The nice thing about sending a native file upload to the browser is that you can control it within a div tag or some other element and then replace the contents, creating a web page that degrades gracefully... i.e. if your file upload control fails to initialize for whatever reason, the user still has a file upload control.

Feedback response number WEBB7VQTCU created by ~Holly Brefreemannivu on 09/09/2009