Adobe Lightroom 4 is a pretty powerful program and can be used for a big percentage of your photo editing and organisational needs.
One of the reasons its fast becoming the all round editor of choice is its dive-in simplicity when compared to more traditional photo editing solutions.
This belies its power, and a lot of its oomph is under the hood out of sight and not normally mentioned in tutorials. Over time and often purely by accident I have come across hidden features which make life using it even quicker and easier.
When teaching basic Lightroom I introduce my students to the concept of using shortcut keys to speed things up. A lot of these shortcuts can be modified though by using the Control(PC) key, or Command(Mac) to give a variation or modified control of that particular function.
Here's one I find useful and quicker than selecting the tool itself. If you are in the Develop mode pressing the 'R' key will take you into the cropping tool, you may know that already. If you then click on a point in the picture whilst holding down the Control or Command keys, it will automatically select the ruler tool, so you can now straighten that horizon or eyeline very easily and without having to directly access the menu. A real timesaver.