Cheap ass solution:
Tools needed:
1) Fan
2) A Plastic Tub
3) Big Block of Ice
Steps
1) Aquire Ice
2) Place Ice in Tub
3) Turn on Fan
4) Freeze Ice when Melted
5) Repeat if Necessary.
See!? It's reusable and portable!
EDIT: I don't have AC either so usually open the windows up at night and let the window fans run like hell and then close everything up at 8 or 9 in the morning. When it gets really bad and I need AC, I stick my head in the freezer ;-) Instant relief!