To add something so that hopefully everyone sees it
#1 Unhide file extentions on your machine
#2 Any file of these types, do not open:
PIF, SCR, BAT, COM (yes its a file, Component Object Model), CMD
EXE is open at your own risk, but I would NOT advise it since there is really no reason to send one unless you were expecting it from the person.
With the ZIP files, open it freely, but if what is inside follows the above files, forget it.
One technique is to send a file with a faked extention, like hotchick.jpg.exe
If you are a computer nerd you already know these things, one alternative is to look at the file header if you have a hex editor as they may use other techniques as well.
I think that covers the basics.
