NASA's Zero Gravity Pen

When NASA first started sending up astronauts, they quickly discovered the ballpoint pens would not work in zero gravity. To combat the problem, NASA scientists spent a decade and $12 Billion to develop a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to 300C.
The Russians used a pencil.

One more funny thing that's ... well not really true.
Let's first remember that the NASA budget in the 1960 was $500 million and in 1965 it was $5.2 billion. They simply didn't have the $12 billion claimed in the joke.
NASA did not spend any money at developing the pen at all, the only money they spent on it was to buy it.

The Fisher Space Pen Company did on the other hand spend millions of dollars on developing the pen. American and Russian astronauts still us the pens and you can buy one of your own if you like. Here, the price tag is $50.