My guess (based on the photo, that's all I can do) is that your third
molar is starting to erupt, and this is normal.  I can't tell whether
your molar has enough room to erupt normally into your mouth, but if it
isn't hurting it's not an emergency.  You should go to the dentist when
you can to see what the position of the third molar is, and whether it
needs to come out.

Steve

http://static.zooomr.com/images/429839_191c540f78_o.jpg

Yesterday I noticed the the gum behind a molar was pulling away from
the tooth.  It doesn't hurt, but the part that has essentially 'pealed
back' is now flopping around loose in my mouth.  Obviously the
immediate answer is to go to the dentist, but I'm an international
student outside of the US and want to avoid the dentist here unless
absolutely necessary due to the bad reputation of dentists in the area.

Is it likely that the gum will magically re-attach itself just as it
magically pulled off, or am I experiencing something more serious that
needs to be dealt with immediately?