Route alias

Hi,

the Rails app I am currently working on will have a public API (REST) so other can communicate with it. I am thinking right now which URLs to use. I saw some apps which use a prefix for their API, e.g.

/api/v1/projects...

I am not quite sure if this is really necessary, I mean if the app is quite RESTful, there shouldn't be much changes to the interface?

If I use the abovementioned approach, I still don't want to show these ugly URLs to my users. So I need to have some kind of URL aliasing so that actually

/projects points to /api/current_version/projects

How can I do that in a relative easy, dry, and clear way.

Comments, tips are appreciated. Thank you