Of the currently available netbooks (although more are on their way soon), the Acer Aspire One is, IMHO, the coolest - it looks more idiosyncratic than its rather more mini-me brethren, plus it has that clever dual-SD-card thing going on. It's the geek's netbook.
It's also the cheapest of the 8.9"-screen bunch. It was originally supposed to come out at £200, but emerged at the £220 price point - psychologically just out of that why-the-heck-not bracket. Now, according to PC World's website via MoDaCo, you can get it for just £199. But wait - enter in the code 'YAWAUG08' and you get it, delivery and VAT included, for just £189.05. Bargain. Cheers for the tip-off, MoDaCo!