Stamp-size satellites

The cube sat program mentioned in the article has been a great success. Launch opportunities often arise when scheduled launches have spare payload space, or when a new launch vehicle is being tested and either the launch company isn't willing to handle real (meaning very expensive) payloads, or the companies seeking to put their expensive payloads into orbit aren't willing to roll the dice with a new launch vehicle.

As an example, lots of ham radio satellites have gotten into orbit this way.