Cereproc is audible versatile, but could blow a louder trumpet locally! In 2008 CereProc announced 100% revenue increase for the year plus a major partnership with ATR of Japan. If you need voices, this is where to go. a leading speech synthesis developer, with research and development facilities in Edinburgh and a commercial HQ in London

CereVoice is a new generation Text To Speech (TTS) engine designed and built, incorporating the latest  in speech technologies. The CereVoice system is  available in two variants - a pure unit-selection system, suitable for high volume telephony solutions, and a hybrid system using an innovative combination of a unit selection and parametric engine, for markets where reduced cost is of vital importance.

CereVoice produces speech output that is both emotional and characterful in content, allowing users to listen to long periods of synthetic speech produced from any source, without becoming bored or distracted by the lack of human character of the speech.

FreeAgent Central simply claims to be online accounting Nirvana!

Impressed by these, it could be SME's might like a  quick whirl through the rest up for awards as their services might find useful.

Huddle mentioned three, not in the current Business Week list.
Ning (US) create your social network in such a neat soft sell approach.
Spotify (Luxemburg, UK HQ and R&D in Stockholm) offers a world of music.
Slide (US) offers slide show creation, and is of SuperPoke, Top Friends, FunSpace, and SuperPoke Pets fame, monthly reaching more than 155m people in Facebook, MySpace, Bebo, Hi5, Orkut, Friendster, and Tagged.

The other best enterprise/B2B startups

Adconion  (US) audience network

BlueKiwi  (US Kids in the Workforce

BusinessITonline (London) small business software, office supplies and business search

Coclarity (Ireland)  co-cordination project platform.

Corebridge (UK) unified communications.

Edocr (Daresbury) unleash public documents on one platform.

Garlik (whiff of werewolves & plague protection) offers personal information ID theft, fraud data patrol for individuals & business
 
Huddle (London) At just $15/month, Huddle.net provides all the online collaboration, sharing and project tools for team, partners and clients to work together,

Knowledgeplaza.be  (Belgium) the place beyond search...where those who search meet those who know.

MirriAd (London) In video advertising and product placemend with  embedded advertising, digitally placing brands, products and images into video content ranging from Studio and Broadcast content to TV, Online and UGC.

Mtivity (London) web-based marketing & print management tools to improve marketing process leaving more time for inovation, inspiration and creativity.

Mydeo (US & UK) media streaming and hosting. No setup costs, no minimum contract, free online reporting and instant setup

MyID.is (?) certifying your digital identity and to allow you to claim all your digital profile/website/blogs and to manage your online reputation.

OpenX (london)platform  a complete foundation for building your online advertising business in innovative and flexible ways.

PeoplePerHour (London) outsource work to rated freelancers, quoting is tricky.

Proofhq (Middlesex). Upload your file proof, pick reviewers it converts your file to a web-based proof and sends your reviewers a personal link to the proof.

Programeter (Estonia) ( originally SourceKibitzer) tracks the current status of your software project, its changes over time, how the key factors of the project affect it Tracks status of features, tasks, bugs, even programming team's knowledge for project control

Skimlinks.com (Australia) Convert your links into affiliate links. Access to 6000+ affiliate programs with no admin effort. Reporting shows what users click on and buy.  Broadest support for deep-links

Smarta (London) business support, advice & information for startup & entrepreneurs

Sosius (Thame) on line share & collaboration online workspace, accessible from any PC or Mac, that lets you create and collaborate. No software to buy/set up.

Tactilecrm (London) lets you record every email, telephone call, note, activity and meeting, so colleagues can quickly see every interaction.

TrampolineSystems (London) intelligence tool tharnessing real-time social network analysis for organisation change and restructuring programmes. Uses Sonar diagnostic enterprise search that connects you directly to people with relevant knowledge and expertise.

Viapost (London) an alternative mail service that allows you to send physical post direct from your PC. A secure, high-quality, confidential way of printing and posting that saving both time and money.

VideoPlaza (Sweden) an ad server designed to help premium publishers manage, display and track advertising in and around their online video content.

Woobius (London) collaboration hub for architects and engineers

Yasmo Live (London) locate  people you wish to network with at social and professional events, by seeing their picture-based profile on your mobile phone.

Youcalc (US)  Smarter widgets. Create and share custom reports and analytics on data from SaaS systems – zero coding required! A library of analytics apps for CRM, sales, marketing, service/support and project management, and live data connection to  SaaS systems (Salesforce.com, Basecamp, AdWords, Google Analytics, Highrise CRM, MailChimp, etc.)

Yuuguu (Liverpool) cross network instant messaging, instant screen sharing,
real time collaboration, web conferencing and remote support

Zenbe (US)Create focused conservation with people that matter..shareflow, mail & lists.

Zendesk (US) help desk system in a hosted environment  is the single-point-of-contact between your end-users and you as a service provider, makes it possible  to offer a professional-grade support service and capitalise on valuable user feedback.

So, for all that information, Huddle got Gaberlunzie's vote.