There were complaints about battery life with iPhone OS 2.1, but many on the various internet channels seemed to think OS 2.2 fixed that up rather nicely. Reports since iPhone OS 2.2.1 have varied more widely. Some seem to think it's fine while others, including well know tech pundit Leo Laporte, keep saying they're getting worse battery life since the last update.
What's happening with your iPhone? The same? Better? Worse? Can you make it through a day? And what's with the up and down between firmware? Is Apple playing some high-stakes balancing game between battery life and signal reception?