Toshiba makes a bluetooth SDIO. I'd love to put one in the SD slot in my 700m and use a BT mouth and keyboard. I can't justify the price though (the card is $99 new or $60 on ebay) Plus there is no guarantee it would even work correctly in this setup.
I've seen most of them here in Taiwan. They could be useful on PDAs, but with firewire and USB 2.0 (and PCI Express coming) I don't see the need for them with notebooks. Heck, most of that stuff is built-in on top end PDAs these days anyway.