Hi Si - Yes, you can do this by going to your My Account page and ticking the box to let people that you are following see your private routes. Then you just need to "follow" the people you want to share the routes with (you can do this from your personal home page). Of course they'll need to be registered on the site first, so that you can follow them.
John
Is it possible, or will it be possible to share a ride without making it public?
I don't tend to make my rides public due to them usually starting and ending from my house (call me paranoid) but would often like to share a route with friends.
Thanks
Si