The trackpad on my Macbook Pro just started acting oddly. It's randomly clicking (which might cause me to switch programs), right-clicking and even once my screen even showed the swiping animation as if I was trying to switch to a different desktop.    

Part of me fears that this is some sort of joke hacking attempt (I know of a USB device you plug into someones computer and it randomly moves their mouse and types on their keyboard), but there is nothing plugged into my machine and I just turned off the Wi-Fi and watched as this web page tried to close, the mouse right clicked twice, highlighted a word and clicked "Paste and Match Style" in the Chrome right-click menu.
Also as I've been typing (with my Wi-Fi turned off) the mouse has randomly been clicking inside this question and changing where I am typing.  

I just plugged in a USB mouse which seems to work fine but the trackpad is now nearly useless. I can't even move the mouse cursor more than a few centimeters with it.

Is this a common issue?
EDIT
I think it is dying actually. I can now click but not move at all with the trackpad, while a regular mouse works fine.
EDIT 2
And now it seems to be working again. I turned on the option for "Ignore Trackpad when Mouse is plugged in" under Universal Access. I cleaned the trackpad with rubbing alcohol, I whined and complained for a few minutes to my dog, turned off the "Ignore Trackpad" setting, unplugged the USB mouse, and the Trackpad appears to be working mostly normally.
If I run my finger across it at the top or bottom portion of the mouse, it works, but there is a line horizontally across it (almost exactly where a physical trackpad button would end on the old trackpads) that is "dead".  The mouse stops moving, or moves sluggishly when hitting that spot and that "spot" goes across the whole trackpad.


Question: Snap individual vertex of the selection to closest vertex
Answer: Perhaps the Selection to Grid option from the (Shift+S) snap menu could be of use? It moves each selected object/point to the nearest grid point.

The grid can be configured in the Display panel of the 3D View's Properties shelf.