Follow other portal user's Ideas

Some of our more active Portal Users have started to recognize each other's names, and are often interested in each other's approaches.  

If I've seen submissions/votes by Tom Smith that I often like, I want to click on his profile and subscribe to "follow" him and be notified of his future submissions/votes.

OR

I'd like the ability to filter Ideas by "Tom Smith" to see Ideas he has already submitted/voted on.