carsonmcdonald/direct-browser-s3-upload-example — pull request #1 by gotjosh (2012-09-07 19:13:37+00:00)
Title: Tidying up and a bit of fixing

Turns out I was getting the 403 error because some of the files I tried to upload either contained spaces or special characters and it seems that S3 is rather sensible to these. By parameterizing the name before making the request this solved all my problems with the signed URL's perhaps, this is what happened to some of the users that posted in the comments in your blog post! Thank you very much for this and the help :)