Found this
INSPIRE 702911 online. I haven't bought one, but I'm curious if it works with large WAV files and SDHC cards. Could be cool. Add your own 350GB disc.
NSPIRE 702911 - 2.5" Hard Drive External Enclosure with Card Reader and One-Touch Copy
* Supports Hi-Speed USB 2.0 data transfer rates of up to 480 Mbps
* Reads eight flash memory card formats – convenient one-touch copy easily transfers data without a PC
* Lightweight, compact design and optional battery power stores, reads and shares photos and files almost anywhere
* Fits standard 2.5" PATA (IDE) hard-disk drives with easy, quick installation
* Windows compatible, Plug and Play, hot swappable
* 44 pin IDE internal connection
* Hi-Speed USB 2.0 mini B external connection
* VIA (VT6205A) and PMC Flash (MKRL4) chipsets
* Supports Memory Stick, Memory Stick PRO, Memory Stick Duo*, Memory Stick PRO Duo*, SecureDigital (SD), TransFlash*, MultiMediaCard (MMC) and Reduced-Size MultiMediaCard (RS-MMC)
* DC power input jack (AC adapter not included)
* 14 x 8 x 1 cm (5.1 x 3.0 x 0.5 in.)
* External Enclosure with Card Reader and One-Touch Copy
* USB cable, A-type male to mini B male, 4 ft. (1,2 m)
* Battery power adapter with cable (4 AA batteries required; not included)
* Travel case with snap closure and storage pockets
* User manual, CD driver and installation screws *Adapter required (not included)