Windows Phone 7 prototype by LG , boots up in around 30 secs. This is the fastest boot up time in smartphones till now.
The build present in the prototype was not final; and it was a cold boot, after removing and replacing the battery. What’s remarkable is that as soon as the lock screen displays, it’s fully initialized and ready to be used.
This has been reported at istartedsomething :
Smartphones are not known for the fast boots and the fastest Windows Mobile 6.5 device on the market today, the HTC HD2, takes easily a minute to boot and at least a further 15 seconds before you dare to touch it. Earlier builds of WP7 at MWC took at least a minute to boot too. Considering this is still a work in progress, I’m optimistic they’ll improve it even further
This operating system pretty much looks like that it is ready to be used and they have made number of improvements in the OS since its launch at MIX10.
You can see view screenshots of Windows Phone 7 (latest build) here.