MobHappy just profiled a new photo/video upload site called Mojungle.
After having done some experimentation in this space (http://www.where.com), I’d say there are several things that can slow these types of services from reaching the mainstream:
1) Mobile data plans can be expensive and complex.
2) Phone interfaces for sending photos/videos to an email address can be cumbersome; 10 taps before entering the destination email address is not uncommon.
3) Typical web marketing techniques rarely succeed in getting people to pick up their phones and try something new (it’s much easier to get a mobile user’s attention when they’re bored and offline).
The good news is that the mobile space continues to grow and the technology is in place to put our mobile photos and videos online and share with others.