A while back I posted a DIY Variable Voltage E-Cig how-to on Instructables.com and it eventually got picked up on HackADay.com here. I look at articles that make their way to HackADay as successes so when I found out that mine had made it I got excited and nerded out.
Since then I have taken feedback from readers and updated the schematics to be more efficient and longer lasting. I have plans to one day publish an Arduino based variable voltage and wattage version with display that will fire sub-ohm coils.