The SLIMP3, released in 2001, is the first generation network media player, produced by Slim Devices. It plays MP3, WMA, AAC, FLAC, WAV, OggVorbis, Shoutcast (and more using plugins), which are streamed over a network from Slim Devices' custom software, Squeezebox Server.
Though getting harder to come by, these are beautiful units. If you come across one for sale on EBay, then buy it quick before anyone else notices!
Newer versions of this device came with an actual SLIMP3 remote, as opposed to the old-school Sony remote.
Slimp3uk.com (the UK outlet that no longer exists) also sold extra remotes and an 'upside-down' under shelf mounting perspex bezel which replaced the standard display and allows you to mount the unit under a shelf).
The SLIMP3 was succeeded by the Squeezebox.
Squeezebox (hardware comparison)
SLIMP3 - SB1 - SB2 - SB3 - Transporter - Duet (Controller - Receiver) - Boom - Radio - Touch