The best thing ever happened in my girlfriend's apartment building...
My girlfriend and I were watching tv, and then the cat started howling at the bathroom and then ran and hid under a chair. Then, the toilet began gurgling at such a volume that we could hear it from the other room.
We got up to see what was going on, and arriving in the bathroom we watched the bubbling stop, followed by all the water drain from the toilet -- the water was then replaced by soap bubbles. Not just some soap bubbles, but lots of soap bubbles. The toilet began to fill with soap bubbles, and once it reached the point where it was looking like it was going to overflow with suds, I flushed it to see if that would fix the problem. It didn't. I started pouring pitchers of water on the suds to try and get rid of them, and it managed to keep the suds at bay until the gurgling stopped and the fresh flow of soap was ended.
My girlfriend then went to talk to the building manager, and he/she (irunno) said that someone on the 6th floor had been cleaning their apartment and had dumped all the soap down the drain -- not necessarily an unreasonable thing to do. But...
My question is, how much frickin soap did that person have to use so that they managed to create air pockets in the plumbing system and force soap bubbles to erupt out of people's toilets on the first floor? That's a lot of soap.
The whole time it was happening I couldn't stop laughing. They must have poured, like, an entire bottle of sunlight down the drain: my girlfriend's bathroom smelled of lemon detergent for hours afterwards.