Couple of good London startups I know from friends :<p><a href="http://www.nestoria.com/" rel="nofollow">http://www.nestoria.com/</a>
Property search engine, which is doing really well, profitable and spreading base across Europe. Started by ex-Yahoo people.<p><a href="http://www.mendeley.com/" rel="nofollow">http://www.mendeley.com/</a>
"Like iTunes™ for research papers. Mendeley is a free research management tool for desktop &#38; web."