Yes, it's possible. I would suggest using one of the uploaders like the one from YUI (don't have any experience with that), PLUpload or jQuery File Uploader. You then need to create an XPage that you send the files too from the clientside library and process them on the server. This answer on StackOverflow should also point you in the right direction: http://stackoverflow.com/questions/17073250/how-to-upload-and-save-an-attachment-via-xpages-java-bean.
I also have a project on OpenNTF that shows how you can do multiple file uplads with XPages:
(I wouldn't recommend that one anymore since it uses Flash, but maybe you can grab some ideas from it).
Another example I did is the (HTML5) image uploader (including drag-n-drop) in Bildr. Also available on OpenNTF.