I need information on what it takes to turn around a Boeing 727 after
it has landed.  I need to know what the pilots, flight attendants, and
maintenance crew have to do in order to get the airplane ready for the
next flight.  This was assigned as a class project and the turn around
time needs to be in 30 minutes or less.  Thanks for your help!

do any airlines still fly a 727?

i fly small planes... the basics are what's called a 'pre-flight'
(pre-flight checklist).

its simply a list of things to look at and check for proper operation
before the next flight. look over the airframe for damage, make sure
all the flight controlls work, lights work, etc. all planes have
custom tailored pre-flights for them. i'm sure passenger jets have
very in depth ones. Each group of people would have the same (ground
crew, flight attendants, pilots). in my training, one of the things
stressed was to check the color and level of the fuel visually... make
sure you didn't get the wrong stuff (prop planes use fuel that's blue,
jets use fuel thats clear).

One flight despatcher told me that they used to have a competition for
the fastest turnaround - she managed 23 mins which broke the record
(for a full ontake of passengers).

I've been in the cabin and cockpit a fair number of times during
turnarounds, I can't remember the cockpit crew getting out, but I
remember a couple of cabin crew nipping out to buy bottles of Mateus
Rose at Funchal.

Refuelling was pretty fast, and mostly the cabin crew scurried around
picking up litter - tidying the seat pockets etc - catering trolleys
were exchanged with those in the hold, but I can't recall any major
activity during a 'remote' turnaround - not even cleaners.

Most activity (for short haul) takes place at base. Even then, there
is pressure to get the aircraft in the air ASAP.