The new Microsoft Mobile Memory Mouse 8000 combines a cordless notebook mouse with a 1GB flash drive built into the USB transceiver.  This effectively conserves scarce USB ports on some laptops, though I imagine there will be perplexed users who unplug the drive and wonder why their mouse stops working.

Available in the UK for about £50. Carry up to 1GB of your 'learning objects'/presentations etc with the mouse that can facilitate learner participation. Find out more at http://www.microsoft.com/hardware/mouseandkeyboard/ProductDetails.aspx?pid=098&active_tab=overview .