Tankless Water Heaters?

Hey -- anyone out there use a tankless water heater? I'm replacing my big gas heater with a wall-mounted electric tankless water heater, and need to get some info from those of you out there who already have them installed. Any recommendations? :)

BTW -- I'm back, but I'm not really back yet. I'm hosting, and won't be free until after the 16th. I haven't really been able to read and respond to e-mail, so if you want to get ahold of me, please call my mobile phone.