If you haven’t looked at the Ext JS framework yet, you really ought to. We use it extensively at work and we are quite happy with it. I just wanted to point out that the 2.0.2 version of Ext has come out. This release was mostly related to the new Adobe AIR 1.0 that was recently released. Currently at work we don’t do any AIR related things, but we’ve looked at dabbling in that field in the future. That being said, there are a few custom Ext components that were put in the Simple Tasks example that came out with this release. The TreeList, custom grid columns, and a switch button are all used in Simple Tasks, but their code could very easily be copied from that example to be put into any 2.x-compatible code.
