Omar Al Zabir, co-founder of Pageflakes, describes in detail how you can build a personalized homepage similar to Google IG using ASP.NET AJAX and .NET 3.0 Framework.
"Among [the popular AJAX start pages], Google IG is the simplest one. The one I have built here is something between real Google IG and Pageflakes in terms of Ajax and client side richness. Google IG is mostly web 1.0 style postback model and it's not really that much of Ajax. For example, you see it postback on switching page, adding new modules, changing widget properties etc. But the one I have built here is a lot more Ajax providing rich client side experience close to what you see in Pageflakes."
The result is DropThings, a site that mimics Google's Personalized Homepage, but has a much worse performance.