BlackSpider is an email- and Web-filtering service. Variously described as "managed", "hosted", "on demand", or "in the cloud", the BlackSpider service competes with the bigger fish such as MessageLabs, Postini, and Microsoft -- the service it acquired with FrontBridge.
In related news, BlackSpider revenues are now about £5,500,000 (US$11M at today's excruciating exchange rate). 40% growth ain't bad.
PS: calling SurfControl and Websense's PR/AR teams: how come I had to read about this in the Sunday Times first? (Bizarrely, in an article about Peter Gabriel's We7.)