I\'m, going to write a web app, which should be CRUD accessible from both, the web and native mobile device apps. For the latter i\'m definitely committed to a REST API. Is it p
As of 2015, look at Gadi's answer for the Meteorpedia entry on REST APIs, and at krose's answer comparing REST API packages. Discussion for folding REST APIs into core is on Hackpad. This question is a duplicate of How to expose a RESTful service with Meteor, which has much better answers. -- Dan Dascalescu
Old answer (2012) below.
For adding RESTful methods on top of your data, look into the Collection API written for Meteor:
https://github.com/crazytoad/meteor-collectionapi
As for authentication for accessing the database, take a look at this project:
https://github.com/meteor/meteor/wiki/Getting-started-with-Auth
Both are definitely infantile in development, but you can create a RESTful API and integrate it with a mobile native client pretty easily.