It must be a laptop (not a PC), I'll mainly use it for internet, watching dvd's, connection to digital camera/ video camera, v. few games.
I assume you don't want a Mac..?
If it must be a PC, given those requirements I'd forget about things like MHz - any modern processor is going to be fine. As others have said, just make sure it has plenty of memory.
My own POV with laptops is to buy one from a company with decent service - apart from memory, other things are fairly unimportant in comparison. Unlike a desktop machine, if something goes wrong with a laptop then more often than not you can't do anything about it. There's no reason why a modern laptop shouldn't be good for five years or more (games excluded, but a laptop isn't a great choice for a games machine anyway). However, one duff component can fast-track it to the bin and that's when the service comes in. Good service will have you back up and running. Bad service will have you paying another £1000 to replace what should be a perfectly usable laptop that just went out of warrenty.
Of course, service has to be paid for - so you either pay more or settle for lesser hardware. Still, modern hardware is pretty much overkill for everything apart from games so it's not such a bad choice to have to make.
And Dell? IMHO they're reasonable machines to buy (especially the desktops, assuming you pick your deal, don't buy the crippled really cheap ones and are happy to replace hardware yourself). However, the service sucks. I'd care about that.
As for centrino etc., i've got no idea. Don't even know what processor is in my laptop
