I rarely use Bluetooth and so have it turned off, but it is useful occasionally. The last time I used it was for someone who couldn't sync their Sony Ericsson phone with their PC. Turned on my bluetooth, and on the phone and the two connected instantly, and it was a smooth process updating the phone's software.
Besides mice and keyboards, a common use is headphones. As Slix says, you are not missing out. It is a tool that is there if you need it.