Yep I'd suggest you look for the Centrino standard (wireless). Even if you don't want that immediately, you will one day. I'd also suggest you look at the Pentium M (mobile) standard processors. They run more efficently (bettery life and cooling) than the standard, but perhaps more powerful Pentiums. If you do go Centrino you are stuck with Intel as AMD haven't really got the mobile market sussed. It's the one area where Intel still have the clear adavantage over their rivals.
Sony laptops are very very nice, but can be a little pricey. I've heard issues about sourcing spares too. Bear in mind that the way laptops are built they have limited upgradeability, and parts generally aren't easy to come by. By going with a known name, despite there being good lesser known makers, you have a better chance of a repairs backup.
I'd be tempted to suggest sticking with HP/Compaq, Dell, Toshiba, Sony. Some good also rans can be Acer and Elonex. Time / Tiny did do laptops through their high street outlets, but they did have build quality issues a while ago, so I'd steer clear now.
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Given what you say about space, rather than portability look at something with a 15" screen, perhaps a widescreen format.
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This looks quite good in your price bracket:
http://www1.euro.dell.com/content/pr...hs1&l=en&s=dhs
you could always have a larger hard disk.