Power Management

[desowin]

I'm rather complete newbie to power supply related issues, basically I know about the 7805 and I've watched EEVblog #139 - Let's Select a DC-DC Boost Converter

I'm searching for solution which would handle following:
-AA (2 or 4) battery input
-car cigarette lighter input
-3.3 V output
-5 V output (but that's just "extra", not mandatory)

If the device is plugged into car cigarette lighter, it should be powered from there - if not, then it should be driven from batteries, integrated charger solution (in case the cells were NiMH or NiCd) is not required
I heard there're PMIC solutions that could handle that, but either I'm searching wrong, or it's called somehow different.

[scrat]

I know National Semi has good online tools, but someone knows better than me. However, I'd try with a parametric search on a semiconductor manufacturer site, as a start.