On April 1 Silicon Graphics Inc., one of the highest-flying companies in Silicon Valley during the early 1990s, sold most of its assets for a price that could have been an April Fool's joke: a meager $25 million. SGI now ends up in the tech graveyard of once-great companies that lost their way. Some had too much hubris or could not change quickly enough with the times, and were side-swiped by newer, cheaper technology.