A way to talk to messaging api of linkedin through rails

Scenario:

I'm a registered user of a site(a rails app).

I have my contacts in linked in whom I would like to invite to see this app(it would be followed up with their registration into this app).

For this , I would be sending them a message with a subject and body.

Rays of Hope:

I need to make use of the messaging api of linkedin and make it talk with my rails app. I can't use the connections api of linked in to retrieve the email addresses as basically any of the linkedin api's don't expose my(the registered user of linked in) contacts email.

To talk with the connections api in my rails app, I was making use of the linkedin gem. It doesn't look like this gem as of now has support for the messaging api of linkedin.

Finally:

Any ideas where can I get started on this..?. I'm kinda clueless as I have never played around with api's directly, ..yet..:).

I'm on Ubuntu 10.04 OS.

Thank you