[jacquesm]

This falls - as others have already commented - in the 'knows just enough to be dangerous' category.

Please use LEDs, don't even bother messing around with opto-isolators and so on unless you have experience with both mains electricity and designing safe circuitry.

[tehwebguy]

Agreed 100%. Not happy with the Pi's 3.3v pins and want to light something brighter than a couple of LEDs? Try this:

- 12v power supply (from like anything in your house)

- 12v LED strip (super cheap on eBay or basically anywhere)

- This awesome MOSFET from Adafruit http://www.adafruit.com/products/355

This is what I used for a cool RPi + RFID + LED project this year, write-up coming eventually, here's a clip for now: http://vine.co/v/bvZQVJLnemh - my example only has a few LEDs but in the final product I used strips with about 30.