In addition to the headsets and car-kits, you can bluetooth media files and contact and address books to and from. I don't see where you can BT attachments, such as docs or spreadsheets. Its something that would be useful. Sometimes I'll get an attachment on the BB, will have my notebook with me, but won't be in wifi range and won't have mastered the quirks of tethering, and I'll be stuck with peering at the attachment on the BB.