ASP.NET File Upload like GMail

Ajax Uploader is an easy to use, hi-performance File Upload Control which allows you to upload files to web server without refreshing the page.

It allows you select and upload multiple files and cancel running uploads, add new files during uploading.

Ajax Uploader allows you to upload large files to a server with the low server memory consumption. The look and feel of file upload controls can be customized to seamlessly blend into your website design.

http://ajaxuploader.com/