SplashTop is a new "feature" or program that is starting to appear on some laptops and noteboooks. It appears as a Web button on the computer that you would press instead of the power button. Pushing this Web button tells the computer to boot this new special program or OS instead of going to Windows.
The benefits according to the SplashTop website are as follows:
Fast - Be online seconds after you turn on your PC. Why wait for Windows to load when you could be surfing the web right away! (True, pretty fast boot)
Safe - Surf the Web safely, immune from the malware that targets Windows. (True)
Eco-Friendly - Give your PC a rest when you do not use it. Splashtop boots quickly so there is no reason to leave your PC on all the time. (This is a load of hooey)
What are the problems? Some people have complained about YouTube issues and it seems easily corruptible. The major issue is if your computer is no longer bootable it is not supported directly from the SplashTop website but only from the OEM vendor. In the example I'm referring to, Sony Vaio uses it under the OEM name of Quick Web Access. There is little to any help available from Sony if you are having issues and SplashTop itself won't help you because they are selling the program to Sony, so you are not the customer, Sony is.
Do the benefits outweigh the pains? I believe so. If it stops working and it's beyond you or your poor computer geek friend who you rely on and abuse and don't pay, then you can just not use that button/feature anymore.