The Official Gmail Blog has an entry up talking about their new Gmail Tasks web application.
The nice part is that not only can you use this application via the web on your computer, but on mobile devices such as the iPhone via the mobile browser. Google even went as far as posting a quick how-to video on getting the app to show up on your home page:
[kml_flashembed movie="http://www.youtube.com/v/AbiMbmq3JG4" width="450" height="350" wmode="transparent" /]