Seems like Google has a new test site -  Searchmash, there is almost no reference to Google on the website and if it wasn't for confirming the netblock owner as Google Inc via Netcraft myself I'd have thought it was fake.

Domain searchmash.com
Netblock owner Google Inc.
IP address 216.239.57.147
Nameserver ns1.google.com

Anyhow they have a couple of experimental interface ideas and you can vote YES or NO on how useful you think they are.  Talking of interface tweaks I notice Google.com has a new homepage widget that displays useful additional links to their other such tools when you click the more >>  button, but it isn't live on Google.co.uk yet.