How do I reboot Samsung Galaxy S when it locks up? Is pulling battery bad? My Samsung Galaxy S (Captivate) occasionally locks up, so that the screen freezes and it doesn't respond to any user input.  I also cannot hold the power button down to bring up the menu to Reboot, Turn off, etc...

The only thing I know to do is open the back and pull the battery out and turn it back on.  

So, my questions are 
1)  Is pulling the battery to hard shut down harmful to the phone?
2)  Is there some button sequence I can press to restart the phone?

I'm running a 2.3.4 Gingerbread based ROM.
Android is pretty resistant to faults resulting from sudden power loss, but there's always a risk of data corruption/loss, depending on open apps and files at the moment.

Have you tried holding the power button longer, for about 15 seconds (until the screen goes black and the normal startup screen appears)? On my Galaxy S this triggers a hard reboot, meaning that the phone forces itself to restart without regard to the usual shutdown process. I'd think it's a bit friendlier than pulling the battery, but nevertheless, it's a "wrong" way to reboot.