A good news for those who want to try iOS6 and haven’t gotten their UDID registered with Apple . If you have previously gotten your UDID registered for iOS5 beta , for the same phone iOS6 will work flawlessly

To install , all you have to do is download the IPSW file, many are floating around on torrent sites , I used the IMZDL one , their size could be upward of 600mb.
Connect your iPhone / iPod / iPad to itunes , click on the device name and press Shift for Windows or alt/option key for OSX and click restore .
Point it to the downloaded IPSW file and in 5 -10 min your phone will be running iOS6.
Apple needs to activate your phone so either connect through iTunes or a WiFi network else your cellular connection will not work.
We at SenseApplied have tried the above method and successfully running iOS6 Beta 3 on our iPhone 4 however we take no responsibility if your phone gets locked or renders useless , kindly proceed at your own risk.