Thanks to ASP.NET Pro mag - paraphrasing many of these tips.
Use SmartNavigation property on the page. Persists the scroll position and focus between postbacks, helps with flicker between pages. For up-level browsers, keeps only the latest page in the browser history. No problem with lower level browsers.

Use System.Drawing functions to generate graphics on the fly. You can create a "page" that is entirely the GIF/JPG image, and stream the image back in the Response.OutputStream, and set the ContentType to "image/gif".

DataGrid confirm on delete button:

OnItemCreated()

{

	if ( e.Item.ItemType == ListItemType.Item || 

		...ListItemType.AlternatingItem )

	{

		WebControl btn = (WebControl)e.Item.Cells[0].Controls[0];

		btn.Attributes.Add( "onclick", 

			"return confirm( \"Delete this row?\");");

	}

}

Add DataGrid row numbers:
(similar to above OnItemCreated() handler

	...

	e.Item.Cells[0].Text = (e.Item.DataSetIndex+1).ToString();

Cause button click on Enter key. Only one line of code, hooks up the button of choice:
Page.RegisterHiddenField( "__EVENTTARGET", "BUTTON_ID_HERE" );
(This doesn't work when certain controls have the focus, such as multiline edit controls)

ASP.NET Configuration Files

Normal handling of configuration/appSettings data is done by NameValueFileSectionHandler, find this in the machine.config section with "appSettings". This tells what assembly/class will handle each section in the config files.
You can override this with your own class and setup the config file like this:

<configuration>

	<configSection>

		<remove name="appSettings" />

		<add name="appSettings" 

			type="MyNewSectionHandler, Assembly" />

	</configSection>

</configuration>

Including external file as the configuration (appsettings) data.

<configuration>

	<appSettings file="myfile.config" />

</configuration>

Using external files in advantageous for apps that change the values often, since changes do not touch web.config, and therefore do not cause all the pages to recompile.

Scroll DataGrid in DIV block

Thanks to Jeff Prosise Q&A section of ASP.NET Pro mag for this one. See April 2003 issue for info.
"Scrolling writes the latest scroll position to a hidden <input> tag named __DIVPOS, causing the final pre-postback scroll position to be included in the form's postback data."

<input type="hidden" name="__DIVPOS" value="" />

<div id="theDiv"

	style="height: 256px; overflow: auto;" 

	onscroll="javascript:document.forms[0].__DIVPOS.value=

		theDiv.scrollTop;" />



<% if ( Reques["__DIVPOS"] != null &&

	Request["__DIVPOS"] != String.Empty ) {

	int pos = Convert.ToInt32(Request["__DIVPOS"]);

	Response.Write("<script language=\"javascript\">" +

		"theDiv.scrollTop=" + pos + ";</script>\r\n"); }

%>

Thanks to Intern Joe for showing me the light on this one.

Use ReadXml() method on the DataSet class, then can set a particular "table" in the dataset as a datasource for a DataGrid, etc.

Still have to investigate the details of reading the xml into the DataSet. If there's an associated schema, it's used to build the table relationships in the DataSet. Otherwise, how are the tables created from the xml ?

C# future features

future features for c#, probably with ASP.NET 2.0, Visual Studio 2004, etc