After a really embarrassing session at church a couple of weeks ago, I’ve removed the Windows startup sound from my sound schema. I powered up my UMPC just before the invocation so that I could take some notes later and to my horror found that the system was booting instead of resuming from standby. Just after the prayer was finished (and the room was silent) my UMPC filled the silence with the default Windows startup sound. It felt so loud that I thought the clock would be shaken off the wall!
I was mortified as I felt like every eye in the entire congregation turned to learn the answer to “What in the world was that?!?!” The good news is that most of those eyes gave an understanding, “Oh, that’s just Brian…he’s such a geek” glance in return to my sheepish grin.
So now I’ve made sure that will never happen again…just a tip that you may consider. 
LOL! That’s hilarious!
I can totally relate. I’ve had more than one gadget make an inappropriate noise at church. It’s trained me pretty well to mute everything before we leave.