You can use your keyboard to navigate around the site. There are a few shortcuts:

Hotkey Description
Q Focus search field, if available
A and D, and Go to newer/older page or post
F Cycle post fit mode
E Edit post
P Focus first post in post list
Delete Delete post (while in edit mode)

Additionally, each item in the top navigation can be accessed using a feature called “access keys”. Pressing the underlined letter while holding Shift or Alt+Shift (depending on your browser) will go to the desired page (most browsers) or focus the link (IE).