I've been in a cover band for about 4 years, and I'm comfortable enough with my playing that I can spice things up a bit... I'm not talking about spinning around in circles or doing laps around the stage, but just general things to avoid being a "bump on a log". Heres some of the things I do -
Ninja kicks right before a heavy part
Pointing at people in the audience w/ fretting hand if I'm playing open notes
Putting my left foot on the monitor and leaning down toward the crowd
Raising the neck of my bass strait up and playing like that
Jumping to the beat on heavy parts (rare or else I screw up)
Running across the stage to rock out w/ guitarist
Standing on the drum riser and jumping off
Using my fretting hand over instead of under (index finger to play)
Rotating my torso to the beat
And just generally keeping a wide stance, making sure my head is moving, and eye contact and smiling at the crowd!
Here's a video from one of our shows, not a lot of stage presence on this one though
http://www.youtube.com/watch?v=6GslnOUV3gw
Anyone else have cool moves to change things up a bit on stage from just head bobbing etc?