What's a Play-Yan? The device seems like Nintendo's best effort to match some of the PSP's multimedia capabilities—oh, but they're not competitors, right? Right.
For now, the Play-Yan is only available through Nintendo's Japanese website, and is being offered alone ($49) or bundled with Panasonic's Windows-based MediaStage 4.2 software ($59). It supports 5 hours of movie playback, 20 hours of music on the DS—4 & 16 hours respectively, on the GBA SP. Continue on for the complete specs…
Name: Play-Yan (Model AGS-006)
Size: 58.5mm x 43.4mm x 11mm
Weight: 16 grams
Media: SD Memory Card (64MB to 1GB)
Headphone output: Stereo Minijack
Battery Life, GBA SP: Movie - 4 hours; Audio - 16 hours*
Battery Life, DS: Movie - 5 hours; Audio - 20 hours *
* Battery life calculated with use of earphones; may differ depending on environment and SD card.
Compatible Files:
Video
File Format: ASF (SD-VIDEO Standard)
Video Format: MPEG-4 Video
Screen Resolution: 128x96 (Sub-QCIF), 176x144 (QCIF), 240x176, 320x240 (QVGA), 352x288 (CIF)
Bit Rate: 64kbps to 1Mbps
Frame Rate: 6fps to 30fps
Sound Format: Bit rate - 32kbps; Sampling rate - 8kHz
Audio
File Format: MP3 (MPEG1 Layer-3)
Bit Rate: 32kbps, 40kbps, 48kbps, 56kbps, 64kbps, 80kbps, 96kbps, 112kbps, 128kbps, 160kbps, 192kbps, 224kbps,
256kbps, 320kbps, CBR, VBR, ABR
Sampling Frequency: 32KHz, 44.1KHz, 48KHz
ID3 Tag: v1, v1.1, v2, v1/v2 mixed, v1.1/v2 mixed
Examples of Recordable Length on a 512MB SD Card:
Movie Recorded on a DIGA DVD recorder:
Superfine Mode (320x240, 15fps), 1050kbps: Approximately 1 hour
Fine Mode (320x240, 12fps), 430kbps: Approximately 2.5 hours
Normal Mode (176x144, 12fps), 300kbps: Approximately 3.5 hours
Economy Mode (176x144, 6fps), 100kbps: Approximately 11 hours
Movie Recorded on a PC Using MediaStage:
512kbps 240x176 (30fps): Approximately 2 hours
384kbps 240x176 (30fps): Approximately 3 hours
256kbps 240x176 (15fps): Approximately 4 hours
Audio:
128kbps: Approximately 9 hours (accomodates about 170 three-minute songs)
[via GameSpot]

