| \pset pager | toggle the pager for long result sets. |
| update cards set style = '"display"=>"none"'::hstore where id = 35345; | set an hstore field |
| sudo find / -name a_string | search entire filesystem for a string |
| grep -rn select app/views/ | recursive grep with line number |
| |mate | pipe results of shell command into textmate |
| ^↑W | wrap selection in open/close tags |
| Command-Shift-4 | select an area: Take a screenshot of an area and save it as a file on the desktop |
| Command-Control-Shift-4 | , then space, then click a window: Take a screenshot of a window and save it to the clipboard |
| \frac{a}{b} | fraction |
| v \cdot w | dot product of v and w, c must stand for 'center' |
| \|v\| | double bar - norm of v |
| \cos \theta | cosine of theta |
| \big| | single pipe |
| \sum_{i=1}^n | summation symbol |
| ^↑W | wrap selection in open/close tags |
| show entries in sidebar with disclosure triangle | turn on hidden preferences, uncheck the box that says 'open entries list' after sidebar selection |