There was a stray cat that one day just showed up at my front door in the middle of winter, horribly malnourished. It was obviously too friendly to be a stray, so I fed it, and after a few days I realized that it wasn't going home. There was a bad snowstorm coming, so I took it in.
Now I already had two cats, and I knew they wouldn't be able to get along with this new addition, plus we weren't sure if it had even had its shots or anything yet, so I locked it in my room for the night to keep it from the other cats while we waited out the storm. The next day, I brought the cat all across the neighborhood, asking if anybody had lost a cat, but it seemed to belong to nobody. The following day, I let the cat back outside, since I wouldn't be able to watch it while I wasn't home.
From then on, I got into the habit of feeding her every day, so she pretty much became my third cat for a while. But soon my dad came home from a business trip, and I was worried that he wouldn't let us feed a stray any more than we already had. Strangely, though, he took a liking to the cat and even took over the feeding duties, which is very out of character for him.
So it continued on, that every day as I left in the morning, the cat would dart down the street to my front door. And every evening I would find it waiting in the front yard for me to come home.
Eventually, another snow storm came and, fearing for the cat, I brought her inside again. At this point I realized that I couldn't keep this up. So I made plans with a neighbor and I gave the cat to him to bring to his relative who was a crazy cat lady.
I may have only known that cat for 2 months, but I loved it, and I'll never forget it.
Also, recently a new stray has taken up residence under my back deck. Its a real stray that doesn't quite like people. I always see it hanging around the yard, and occasionally I find traces that it has eaten birds that come to our bird feeder, but I don't mind it. I've even gotten it to come to me once, and I've given it the nickname of 'CoolCat'.