This posting is most specifically for Brandon who has been longing for a nano heater. I don't know if I've found anything new, but I came upon a heater at petdiscounters.com/ called the "Junior Aquarium Heater" (just go to the site and click on "heaters"). The ad states that it is a 4 inch long, 7.5 watt, fully submersible, pre-set heater, specifically designed for 2-5 gallon tanks. Cost is $12. Let me all know what you think about the possibility of using this in 1 galllon bowls like mine.
Chris
Chris