1. Morpheus is the principal Greek god of dreams. His father was Hypnos, god of sleep. Morpheus had the ability to take any human's form and appeared in dreams as your loved ones. His brothers Phobetor and Phantasos were the gods of dreaming of animals and inanimate objects, respectively.
The drug morphine derives its name from Morpheus based on its similar dream inducing power.
2. A file sharing client that has used the OpenNAP technology platform, but it seems to have broken compatibility as of lately. It has a web-based search interface, just like Audiogalaxy, though Morpheus searches all kinds of media, not just mp3. It now uses the FastTrack P2P protocol.