Is it possible to track activities across all projects I am a member of instead of just individual projects? I would like to see all of the updates for my projects in one stream not have to go to each project to see what is happening.
You can see all of your own action on your profile page, and your notifications page will show changes for all of the cards that you're assigned to, but there isn't a way to see the combined activity for multiple boards.
I had a similar problem and put together a basic app using the trello api. Try it out here: http://trelloactivity.apphb.com
It only requires read access to your trello boards and will display all activities that happen there.
If you want to you can only display certain boards, see the about page for the features.