Here's my latest PCB design. It's a breadboard-mount DC/DC converter. I run many of my projects off a big 12V battery because 1) I have one; 2) it holds a lot of energy; 3) it can put out a huge amount of current if I ask it to (this can also be bad -- I've smoked several devices when they weren't hooked up quite right and the battery did its thing.)
Anyway, I had dedicated a section of my 3-strip breadboard to power supply generation: 12V -> 5V and then 5V to 3V3. But I saw an interesting SMPS chip, the ST1S10 (pdf), that uses a tiny 3.3uH and very little else to produce up to 2.5A of output. So this is what I built.

The right-hand vertical rail is where 12V comes in, and the left-hand rail is wired around other parts of the breadboard as 5V and GND.
The chip fired up and worked immediately, no questions asked. It's a little expensive, and overspec'd for most low-power microcontroller applications, but if you're doing a bigger project that might need a beefy power supply, this looks like an easy way to get it.
Comments
Board Fabrication
Do you hand solder the board? If so, how do you connect to the ground slug?
Regards, George
I do hot-plate soldering:
I do hot-plate soldering: squirt solder paste on all the pads, place the components, then heat the whole board up on a pancake griddle.