soyo wrote:Something like this? could work, try it.. should not be to expensive...

That will NOT work with a USB key.... There are two types of USB connections, host and slave. A USB slave would be a USB hard drive, thumbdrive, USB key, etc. A USB host, would be the equal to the USB port on your computer; ie. a USB port or interface that you could "hang" a USB device off of.
If you're lookin to expand the storage capabilities of your MPC3000, then I'd suggest goin with either a ZIP drive or external SCSI hard drive. The external drives can be found relatively cheap on eBay, as are the SCSI ZIP drives (both internal and external) A good combination would be to have both a SCSI ZIP and a SCSI hard drive. With that setup, you could use the ZIP to transfer your sounds/samples from your computer into the MPC3000, then save it all onto the SCSI hard disk... just my 2cents.
peace,