BG01 - boto-rsync works similarly to the traditional rsync utility, though not exactly. Here's the basic usage:
boto-rsync -a Your_Access_Key -s Your_Secret_Key --endpoint objects.dreamhost.com /source/files s3:/My_Bucket/destination
Creating the ~/.boto file with your access key, secret key, and endpoint means you can exclude those when typing in the command:
boto-rsync /source/files s3:/My_Bucket/destination
As an example to backup your home directory to a DreamObjects bucket called bg01, you'd do this:
boto-rsync ~/ s3:/bg01/
There are lots of options to boto-rsync, just pass the -h flag.
Object storage is different than traditional file storage and can't be accessed in quite the same ways. It's designed to be accessed via API and even easier, files are retrieved via simple URL.
You can upload a 100GB file to your DreamObjects bucket, you will just need to use something that supports the API. The easiest option, IMO, is CrossFTP since it supports uploading large files in pieces. Options are available here - http://dhurl.org/25h.
Access to that file can be controlled by setting the permissions to private and sending an time-expired link to whomever needs it.