I won't say any more so as not to spoil the surprise, but Splice's 404 page is far more fun than you can possibly expect (warning, it makes noises and uses flash)... I'll post about the rest of the site in a bit.
Posted by Tom Whitwell.
It's an actual Flash synth. This was not possible with Flash 8 or earlier, but with Flash 9 it's possible (yet tricky) to generate digital audio in realtime.
If you'd checked the rest of the site (the new sequencer) you probably wouldn't have said that 'bunch of samples' thing... :-)