I read something that surprised me at first - you can get more battery life by choosing your browser carefully. Then I had a sort of "sober second thought" and realized that of course it matters what software you use. The more CPU you use, the more battery you use. It's compounded if you start to get hot from using all that CPU and the fan speeds up, or if you're giving the hard drive a workout too. But armwaving and "maybe" and "might" can only go so far. How about some measuring?
That's pretty convincing. Read the article for the technical details.
Kate
ps: I have adblocking functionality through a carefully tailored hosts file, so my IE8-and-home-grown-adblock probably means I am maximizing my battery life, at least while surfing. Not sure Visual Studio and SQL Server are particularly battery friendly