Uploading from a DLNA client

I'd love to be able to upload my photos from my phone, or videos I've taken throughout the day to mezzmo.

The DLNA specification calls it a "mobile digital media uploader (M-DMU)"

http://www.dlna.org/digital_living/how_it_works/ (Click on upload photos)

Obviously there would need to be a client on the phone to support this functionality, but what about Mezzmo? Are there any plans to add such a feature?

Yes, we've thought about it. I would roughly guess that if this is ever implemented, than it would be around the same time as the "play to" feature or later :)