I've been doing some Android development work lately (more on this when it's out), so I've been collecting Android design inspiration, as a lot of the conventions I'm used to from iOS are very different on Android.
Android UI Patterns is good blog for this, including their recent Finding Free Android Libraries Online, which covers a few sites which are similar to Cocoa Controls.
Android UI|UX is another good one, covering all sorts of topics including a series on general UI/UX tips. They also do some good Holo redesigns of popular apps.
My other favourite place is still Dribbble, which is great for finding Android, iOS, iPhone or iPad design inspiration.
Back to iOS shortly, for my first proper iPad app, which I'm very much looking forward to!