The last couple months I have been busy testing and searing for a Posterous alternative. I was surprised to learn there really isn't a service that does exactly the same thing--email any digital product to a "storage space" that is private.
I have narrowed down the list to my favorite 4 and put a comparison of them into a chart. I've attached the chart here in case anyone else is trying to solve the same problem. Just be aware these are my observations and may not accurately reflect a service's actual specifications--maybe I missed something or got the details wrong.
In addition to my favorite 4 I have also looked at Google Drive, Wordpress, Ebackpack, Dropbox and Sugar Sync but for various reasons they seem less useful for the job.
In addition, I recently heard about Posthaven, a service being offered by 2 of the original Posterous creators. I haven't signed-up for an account yet but I hope to try it out as its services are developed further (probably May). A co-worker also recently suggested box.net so that might be another option.
If you find a great solution, I'd love to hear about it!