Final update in the Merlin the Cat saga! We found her! Here she is, nomming as soon as she got back:

So, yesterday I made up a bunch of posters and fliers that I put up on poles and dropped off in people's mailboxes. I didn't get all the mailboxes on our street last night so today, Ola and I went to a side street and to do the rest of our street as well. As we were nearing our house, there were still loads of mailboxes to leave stuff in but we only had like 4 fliers left. I saw a guy repairing his car so I went over to him and handed him a flier and he was all "Oh my wife feeds strays! I'll let her know!"
10min later, I get a call from this woman (let's call her EPIC AWESOME LADY) and Epic Awesome Lady asks me more questions about Merlin and how to get her to approach you and stuff, her specific colouring, she tells me she'll keep an eye out, we hang up.
15 min after that, I get another call from her and she's a bit frantic going "Klaudia, come quick! She's here!" So I like tubmle out my front door carrying things that might help me catch Merlin (which turn out to be unnecessary because Epic Awesome Lady has all the cat things) and off I run. Merlin was under the back porch of the neighbours whose backyard touched that of Epic Awesome Lady and her hubby, and he's the one who initially spotted Merlz and she's the one who recognized her. Epic Awesome Lady lured Merlin in with treats, I grabbed her, she's home now, sleeping.
THE END.
What I learned: I'm going to get Merlin and Chipmunk spayed and registered ASAP so that we don't have problems like this anymore.
Thanks for being so epically and awesomely supportive and I shall resume my previously fannish entries and maybe even catch up on my flist...maybe. ♥