Hi,
I have forgotten to turn my soldering iron off once or twice in my time but I have got out of bed many times to go and check !!! A while back I fitted a bright blue LED to the top of the soldering iron station which helps as a visual reminder but recently I found the timer plug below which I have to say I really rate and it isn't expensive at all..... switch it on for an 20mins or an hour and it will shutdown even if you get distracted by beer or the telphone. If this simple tip saves anyone from getting out of bed late at night to check their soldering iron then fab.... if it saves someone having a fire then I guess we will never know.... which is a good thing 
http://www.ebay.co.uk/itm/DIGITAL-COUNTDOWN-TIMER-SAFETY-PLUG-AUTOMATIC-TURN-OFF-13amp-Iron-Straighteners-/251082075138?pt=UK_DIY_Material_Electrical_Fittings_MJ&hash=item3a75a86c02
http://www.ebay.co.uk/itm/DIGITAL-TIMER-SAFETY-PLUG-AUTOMATIC-TURN-OFF-COUNTDOWN-/300525948345?pt=UK_DIY_Material_Electrical_Fittings_MJ&hash=item45f8be0db9
http://www.ebay.co.uk/itm/Hair-Straighteners-Plug-with-countdown-timer-for-safety-/140551413220?pt=UK_Sound_Vision_Other&hash=item20b9845de4
I tried looking for something similar from other countries but I expect I wasn't looking hard enough as I did see anything?