I remember the old B727, they always put the rear stairs down for support when parked to prevent the plane from tilting on it's tail...

Once I was on B737, the front part of plane was quite open and more crowded toward the back. During taxi the pilots called to request kid count, then asked how many open seats there were in F/C. Then said " Fill them up!" We had to scramble to find some lucky winners to fill up F/C and got them settled in 5 seconds.