While I agree a temp controlled fridge or freezer is the best option there's no need to wait for Christmas. You probably have a bucket big enough to immerse your fermenter in now and frozen water bottles can't be hard to come by. You can start contrrolling fermentation temps on the very next batch.
I tried the swamp cooler technique before I got a fermentation-dedicated chest freezer and found it to be a major PITA. That being said, I found the quality of my beers increase 100-fold as soon as I was able to manage fermentation temperatures. This was the single biggest improvement in my beer, bigger than yeast starters, or wort aeration, or even switching to all-grain.
And I have only had one big messy fermentation since - it was after I had transferred a big double red ale to secondary for dry hopping. I thought the beer was finished (in three weeks it had dropped from 1.070 to 1.018). Sure enough, the next morning, I found the breathable silicone bung on the floor of the closet I had moved the better bottle into, and the beer hd begun an active secondary fermentation. I cleaned and sanitized the bung, then put it back on - the beer had no signs of oxidation or other problems... I think the initial fermentation stall was due to a lack of wort aeration (I pitched a liter of brewpub-fresh WLP001), and I have since purchased a wine degasser to drill-aerate wort with.