[snipsnip]
> This is not my area of expertise. Inside a lightswitch covber might be a bit
> of a tall ask. From memory, you need a transformer to get to about 15V AC, A
> bridge rectifier to get 10-15V DC and a 5V regulator (prob. need a resistor
> before or lower the input). But, I could be wrong. Not sure about the
> lightswitch, depends how big it is.

Check out this link for small cheap mains power:
  http://www.edtn.com/scribe/reference/appnotes/md004556.htm

Before I go off and use something like this, does anyone care to tell
me how crazy I'd be?  Or is this accepted practice?

I'm going to start a project soon that will run from mains power and this
looked simple enough.  However, I need to switch different power sources
to control various equipment (and do incandescent style dimming on a heater
element) say, 12VDC, 24VDC and 120VAC.  I'd like to set as few fires as
possible, but I'd like to use inexpensive electronic switching - TRIACs?
Because of the dimming control, relays are obviously out of the question.

I have pretty good digital background w/programming and design, but haven't
done much in the analog world.  Don't want my feet to get cut off.

I'm really asking because I figured I could just use a PIC pin and resistor
to check out zero crossing.  But after that other thread I figured it was
better to ask. :)

Chris