Google has a special Google logo, aka Doodle, for Yuri Gagarin. It is the 50th anniversary of the first human spaceflight.
The logo is pretty cool in that it is animated and you see a spaceship launch off into space. Of course you have the spaceman in a spacesuit and the planet and of course the Google logo.
Yuri Gagarin was the first human to go into outer space and it was on April 12, 1961. His Vostok spacecraft completed an orbit of the Earth on that date. This was obviously done under the Soviet Union at the time.
Yuri was born on March 9, 1934 and only lived 34 years, dying shortly after his birthday on March 27, 1968. Sadly he died in a routine training flight from Chkalovsky Air Base. The reason for the crash is not 100% known but there are plenty of conspiracy theories.
Anyway, here is the logo in animated form:
Another interesting note is that this is not the first time Google honored Yuri Gagarin. They had a logo in 2007 for Yuri Gagarin for the 46th anniversary of that day.
YouTube also has a special logo for the day:
Forum discussion at Google Blogoscoped Forums & Google Web Search Help.