I see that this has been asked here before, but nothing since Meteor.http has been available. I\'m still grasping the concepts of Meteor and file uploads are totall
Since meteor includes JQuery by default, you can utilize a Jquery plugin for that, i presume, something like: https://github.com/blueimp/jQuery-File-Upload/wiki/Options can do the trick for you, and supports both GET and PUT.
Otherwise it would be a pain in the ass to get it to work, but not impossible, since you can access PUT in meteor.
If you would prefer a more pure JS sollution maybe you can look at: http://igstan.ro/posts/2009-01-11-ajax-file-upload-with-pure-javascript.html
And adapt it.
There is no ready made support for file uploads so share what you come up with, i would be very interested!