It would be nice if we could have it integrated the way Facebook is, but I'm not going to complain. I'm hoping LinkedIn will eventually do an 'official' app.
I'm currently trying out two apps: Link 2iN (?0.79) and IN+ Networking (Free).
Not 100% sure yet which one I'll go for but at the momentso far I seem to prefer IN+.
It would be nice to get other people's views on these or other Linkedin apps.