I have a slight pain in my right shoulder from too much mousing, so I’m always inclined to to learn keybindings for those short interrupting needs to reach for the mouse.
As such, the control-l to give focus to the address bar is lovely, and if i press tab, focus moves over to the search field (or, more accurately, the google field :). That is how to google!
Moving between tabs there is alt-1 to alt-8, which will change to tab 1 through 8. Alt-9 will change to the right-most tab. This pretty much makes it annoying to have more than 9 tabs open. (Oh, and if you develop web sites, please do pay attention to the favicon/shortcut icon. When many tabs are open, the title will be truncated and the icon is the last thing displayed.)
For in-page searching there is control-f which makes a search panel appear below the page. Pressing control-f while the panel is visible will give the search field in it focus. Pressing escape will hide it. (What I miss here is the ability to find a link in the page and using only key-bindings follow it/open in a new tab.)
What I have not found so far:
It is also quite rewarding to open up the keyboard shortcut help in google reader (press ? when the page has focus). Shift-N and shift-P goes up and down in feeds. shift-O will open the focused feed. Plain n and p will move focus between items within a feed, and o will open the focused one.
Shift-a will mark everything as read in the currently open feed. And j and k are shortcuts to n+o and p+o, that is, move to next/prev and open it.