Last summer, at a garage sale, I picked up a "Soldering Iron Practice Kit" for $1.00.
I hauled out my soldering iron yesterday afternoon and put it together. (Yes, I did RTFM before starting.) Found a 9 volt battery, plugged it in...
And it worked.
First time in my life an electronics project has *ever* worked on the first try.
And it's... Well, let's just say it's cute and more than a little bit scary. The two red LEDs take turns blinking on and off, and the speaker emits a noise like a European police siren ("EEE ooo EEE ooo...").
I'm thinking of adding Velcro straps, attaching it to a cat, and sending said cat into my daughter's room to wake her up in the morning.
Most fun I ever had for a buck!