Yes, you can use it to take pics & send them to friends by email or MMS (if your phone service supports MMS texts). You'd store the pics on the phone's memory, or an SDcard (if it supports them).

However, to post a pic on PC, I think that you'd have to first upload it from your phone to an online host (google drive, flickr), unless the albums function on your vistiors page allows you to upload to PC (never used it, yet).

USB sticks probably won't work directly with the phone, as it's designed to act like a USB stick itself when connected to a computer.