Consuming Api Data Mobile/Web

Hi,
i have to build a rails app which needs to support web and mobile. my idea is to built an api which can be consumed by mobile.

API:
get /api/v1/movies

for web i can now either query the db directly  Movies.find(:all) or use ActiveResource to call my api.

which approach would you recommend. are there any disadvantages in using ActiveResource for Web?
im trying to avoid duplicate code for maintenance.

thanks

Pete