Some might think it's strange that Heroku denies users to upload to their folders in their app, but Heroku is a cloud solution and having a massive app is not cloudy. So the idea here is that you have services for photos, videos, etc...
Put this in your model:
And then you need a file in myapp/config/s3.yml like this:
Then go signup for a bucket at Amazon S3: http://aws.amazon.com/s3/