The wife is now requesting her own laptop. It doesn't have to be that strong of a thing, though she will invariably use it for some digital photo work besides internet and word processing too.

My main concern is with battery life. My Dell Latitude D600 runs for at most 2 hours, which means it's constantly in the office recharging.

I would even consider an iBook for her, but I have no idea what I'm looking at there. I see some cheap G3s on eBay, but the G4s are obviously faster. What would be the PC equivalent of these? My only concern here is with it connecting to the shared folders on the PC/Linux wireless network.

Also, for the PC side, what CPU should we be looking at for good battery life? Given the Pentium M in my Latitude, I'd expect better performance. What about Semprons? Or Celeron M?

I think a slightly slower processor with good battery life and lots of ram is the best trade off, but it's hard to find reviews that discuss this stuff consistently.