didnt read any responses...but here is mine.

Window A/C. They can be bought brand new from Home Depot for about $350 for a good one. Used...they can usually be found for free. I found my 10,000 BTU A/C for $20 off of craigslist, but garage sales and local newspapers are great too. Just make sure the compressor works. I couldn't get mine to work when I got it, not realizing that it was only 60 degrees outside which was too cold for the thermostat to turn on so the compressor wasnt going on.

Portable A/C can be an ok temporary solution but they are expensive and not nearly as efficient. There really is no other way to drastically lower your temps.