I've discovered the advantages of using an electric pencil sharpener but believe me they are not all created equal! Recently I've tested several different models and can say from experience which one I like the best... but how do other people keep their pencils sharp?
I was told to always use a sharp knife as it doesn't damage the pencil so much, but honestly I never got the hang of it and hacked off huge chunks each time, so now I use a regular hand-held non-automated pencil sharpener. I can safely say I've had this set of pencils longer than any other.
I've got the X-Acto power 3 electric sharpener and I've got a battery operated one from A&W... The battery operated one does the short sharpen but it works great especially when I'm at an art show and have to draw something ... I've tried several different shapeners and wouldn't take for my electric one. It really speeds up the process of sharpening and does damage the pencils... I do run a regular #2 through it every 20 sharpens or so though! This keeps the wax from building up on the blade and the graphite keeps the mechanism lubricated. I learned to do this after ruining one of my sharpeners.
I use a normal handheld. They are cheaper to buy (and replace) than an electric, so you can have more of them for I tend to lose them sometimes I admit, and you have more control on how your pencil sharpens. With electric, you need to either put batteries in them if it has that feature, or be somewhere near an electric power outlet, or get up to sharpen your pencil every five minutes, which can be very distracting, and makes you prematurely lose interest in what you're working on. Handhelds you just find and they are with you anywhere, even when you are not working on a table.