One thing I have started designing is a custom web control datagrid that includes a search function. It is an aggregate of two panels; one with a datagrid that gives a title above the grid and the ability to change the number of displayed results per page, and the other includes a search box that lets you search and filter the results of your datagrid.
It is something that the datagrid should have had the ability to do when it was introduced. You shouldn't have to program the page index to switch to the next page (although it is only one line of code really), that should be done automatically. You should be able to Override it though. When you click on something you want to sort on twice, it should automatically shift the results to a descending order. This is kind of complex so it may be a few weeks until I have it down. Who knows? I will probably go on a shopping spree and create a whole slew (sp) of controls that enhance the functionality of the current controls.
I have an interesting way of using the SetFocus on web items (html or web) using a script that I register. If I enhance the controls, maybe I will be able to include it as a method of the control. Won't that be nice?