The San Francisco Android User Group hosted an event on August 31st, 2010 where Will Shulman, from MongoLab, showed us how to persist mobile app data in the cloud using the incredibly developer-friendly MongoDB back-end. He also showed us how mobile developers could tap into this technology with MongoLab's simple REST API.
Here's the video for Pt. 1 of Will's presentation, an overview of MongoDB:
The video for Pt. 2 of Will's presentation, using MongoLabs to tap into MongoDB: