I just finished Remember Me? by Sophie Kinsella and loved it! The description of the book sounds lame because it's an amnesia story - I know I know, I rolled my eyes at first, too thinking of bad soap opera story lines, but Kinsella makes it work.
There's an "E" character who has automated his house, but he has disco lights and the toilets are on the circuit (making me realize my E/lighting situation could be much much worse).
Even if you aren't a big fan of her Shopaholic books, I still recommend Remember Me?
Kinsella is getting better and better. Can't wait for her next book!