I'm on it constantly, but it doesn't die THAT fast. Mine dies after like 2 or 3 hours, usually more.. It definitely has a huge effect on the battery though. Kyocera sells an extended battery for 50 bucks, that could help.
edit: Well, not on the net the entire 3 hours, but i usually use the internet for myspace and msn messenger aid aim and stuff so i'm on it for a lot of the day.