I use Google Reader all day checking my feeds. Unlike the desktop RSS readers, this helps me keep in sync and saved multiple installations. There are lot of new features added recently, but search is what I mainly use and love it.
I don’t use a lot of keyboard shortcuts. Just ‘j’ and ‘k’ – next/previous item, keep me going. Sometimes, ‘m’ and ‘s’ – mark read / toggle star also helps. ‘?’ displays all keyboard shortcuts.
I always wish, one small feature would exist in Google Reader where I could maximize the feed view and hide other items on the top ( Home, All Items, Starred, Your stuff) which I rarely use.
Just a small arrow, like the one to hide left pane, can be added beside ‘Add Subscription’ and viola, I can see all my feeds and keeps me aware of how many feeds to read.
( just for screen shot, Changed Show to all )