Just posted this on my other blog - www.yachtsecurity.blogspot.com. Relevant here also.
This from the Taser Blog - http://blog.taser.com/2009/08/the-taser-worked/.
The Taser is not a magic weapon. Use it as intended - to temporarily incapacitate an attacker. Then use other means to control the situation (further strikes, better cover position for firearms usage, etc.) or to move to another location (get off the X).
If interested, visit http://www.pamcompersonalsecurity.com/ and buy one (or more).