Hot on the heels of Siri and her huge catalogue of amusing 'Easter eggs', Google has joined in by adding two new personality quirks to its search engine.

Users found out yesterday - and promptly told the entire planet on Twitter and Facebook - that Google can flip around and be tilted with search commands.

Google Barrel Roll
Do a barrel roll

Search for "do a barrel roll" (without the quotation marks) and the entire webpage will spin around once; type "tilt" and the page will tilt a little to the right. Reports suggest that the tricks don't work in every browser, but Chrome, Firefox and Safari seem to be doing as they're told.

Another fun search is "anagram", which Google replies with "did you mean: nag a ram". Also, "recursion" returns the result "did you mean: recursion".

Google Tilt

Click 'I'm feeling lucky' in a search for "Google gravity" and the page falls to the bottom of your screen. Then every item can be thrown around with your mouse. The search bar is still active, though, and your next search results will also coming crashing to the ground.

Google Gravity
Google Gravity (I'm feeling lucky)

Other Easter eggs in Google can be found with the calculator - yes, I've spent a while on this - where "the loneliest number" equals "1" and "once in a blue moon" equals "1.16699016 × 10-8 hertz".

Finally, 'Google gothic' (then click I'm feeling lucky on the first suggestion) brings up 'Goth Engine'.

Google Gothic
Google Gothic

Google engineers clearly have far too much time on their hands and there's a comprehensive Wikipedia page here detailing Google's hoaxes and Easter eggs over the years. Found any more? Let us know in the comments below.