I ran a 20 meter dipole on the third level of the house we were renting when 
I was 15 years young.  Someone had torn down my 80 and 40 meter dipoles not 
once, but twice.  Mom had purchased a house on the other side of town in 
Omaha, Nebraska, and we would be moving within a couple of months.  In the 
2-room finished off attic on the third floor, I had a bedroom and a second 
room for my ham gear.  It was nearly wide enough for a half wave 20 meter 
dipole.  The windows were floor level and had a ledge about 3 inches wide at 
the top.  I used a nail and put in a couple of insoulaters in both rooms and 
strung a 20 meter dipole from room to room but had to bend the ends aroun 
the first insulators of each end and tie them off about 3 feet to the last 
insulator.  I guess you could have called it a lazy Z dipole, haha.  When I 
operated, the wire was about 2 feet over my shoulder.  It was probably 25 to 
30 feet off the ground and I ran a Drake TR4 into it for 150 watts of 
output.  I got S7 reports from the east and west coasts and made several 
contacts but other wire indoor antennas I've tried haven't worked as well. 
Anything outside is going to work better no matter what.  On the other hand, 
a friend here in Denver liked CW and QRP.  He took a spring loaded lamp pole 
from floor to ceiling and put flat insulators at each end.  The lamp no 
longer worked anyway.  He hooked coax to it and worked several stations with 
3 or 4 watts on 30 meters.  So try anything and everything.

Phil.
K0NX