If you use dropbox, one interesting way of managing this could be to create/edit a file like mobile.ini (or other name) in your Dropbox Public folder. It'd look something like:
http://dl.dropbox.com/u/3782156/mobile.ini
It'd be a file on your computer, but also mirrored to Amazon's Cloud. You still just make that 1 change to a file anytime you want, and all your mobile sites will read it and redirect to the new location.
Could be an interesting strategy for managing your simple data like this for other uses. Maybe even add a simple cache layer, to cache the file in your TMPDIR with an expire time like 15 mins.