As of late I’ve been making smaller and smaller circuit boards, fighting for every mm² of space. The typical 6pin ISP connector used for programming a lot of the AVR micro-controllers has been getting in the way more and more.
As the images might show, it was quite a task to assemble this tiny tiny thing. Pin alignment is crucial and it is really hard to do it just by hand. I had to make a little jig to hold the pins in place while soldering.
Pogo pins are little spring-loaded contacts, very handy for making jigs, or making momentary (but electrically solid) contacts. We use them by the dozen for making programming and testing jigs but they’re handy also if say you want to JTAG program a board that you cant solder headers to – just shove these thin contacts into the programming cable and press it onto the contacts.