My next laptop?

[ffutures]

My laptop computer needs are fairly minimal - it's mostly used to read email, livejournal, fanfic etc. over breakfast, watch downloads and DVDs when I don't want to use the TV, and gets taken to games conventions if I want to run my Powerpoint Forgotten Futures ad for several hours on end. I don't actually do much work on it as such, that's mostly on desktop PCs.

Currently I'm using a 14" iBook G4 for this, but increasingly I'm finding that web sites give problems - gmail and ello are the most recent examples - ello just doesn't work, Gmail is getting slow and bug-ridden and keeps telling me to upgrade my browser (I can't). Youtube isn't too good either, though that may be more wifi than the computer itself.

So I'm looking for another laptop for these purposes

• Screen 14" or so
  
• Must have built-in DVD reader (not too bothered about writing them, but don't want to have to keep hooking up a separate reader)
  
• Must have good battery life (some games con venues charge big bucks for main electricity, and I often run it off the battery for several hours at home if I'm not near a socket) and if possible take interchangeable batteries.
  
• Must have USB ports.

Weight isn't a big consideration, if I'm just travelling somewhere I'll generally take the iPad with me, not the laptop.

I'd ideally like something Mac-compatible again, though that isn't a top priority. I really can't afford to spend a fortune on this.

Any suggestions?