The scenario here is I want to apply localization to my web application and place language selection on MasterPage. I have made my own solution and applied this with assistance of cookies. View demo.

I'll demonstrate that in my sample. The sample has a MasterPage bellow is a snippet from its ASPX code:

   1: <form id="form1" runat="server">

   2:     <div>

   3:         <asp:DropDownList ID="cmbCulture" runat="server" AutoPostBack="True" 

   4:             OnSelectedIndexChanged="cmbCulture_SelectedIndexChanged">

   5:             <asp:ListItem Value="en-US">English</asp:ListItem>

   6:             <asp:ListItem Value="ar-EG">Arabic</asp:ListItem>

   7:             <asp:ListItem Value="de-DE">German</asp:ListItem>

   8:         </asp:DropDownList>        

   9:         <asp:ContentPlaceHolder ID="cph" runat="server"/>

  10:     </div>

  11: </form>

Simply when the user selects his language from the DropDownList the page post backs and change the language. More...

UPDATE:
Matt Berseth posted a detailed information about this tip on his post Bug Bash: Enabling/Disabling the ASP.NET AJAX Timer using the Control's Client Side API. Much clearer and explained in details. [May 08, 2008]
----------------------------------------------------------------------------------------------------------------------------------

from about 2 weeks I wrote an article about how you can use ASP.NET 2.0 AJAX Timer control in a real world scenario side by side with RssToolKit.

The idea it to display RSS feed from deferent location in cycle using ASP.NET AJAX Timer. I also had an idea of pausing the Timer when the user move his mouse over the update-able area "Group Box that display feeds inside it". Of course this should be down from client side.

I searched the documentation for Client Side APIs related to the AJAX Timer control but I didn't find any. I had to hack inside AJAX Timer client library downloaded with ASP.NET AJAX Extensions, and I found what I want.

First I though that by setting client side enabled property using set_enabled(false) of the AJAX Timer I could get what I want; actually I was wrong, this will not pause the Timer.

Dig deeper, but not for too long, I found 2 methods _startTimer() and _stopTimer(), those were excatly what I was looking for.

bellow is a sample client code of how you can use these 2 methods:

   1: function startTimer() { var timer = $find("<%=ajaxTimer.ClientID%>"); timer._startTimer(); }

   2: function stopTimer() { var timer = $find("<%=ajaxTimer.ClientID%>"); timer._stopTimer(); } 

The above code assuming that you have an AJAX Timer control on the page named ajaxTimer. Call these method from your client side code, or add them as event handlers on your target elements.

I don't know why these are not documented, or we are not supposed to use them?! Actually I don't know. I thought that after using these methods the browser will cause a problem regarding client scripts, but both Opera and IE worked just fine without any problem. Also I didn't notice any slow down or hanging in both browsers.

Hope you find it useful.

Well, I had a small issue regarding writing a script to clean a database we have and reset its identity columns in all tables. Although the database wasn't huge one (less than 100 tables) I had to trace relations to be able to delete child table's records before parent's ones because of the foreign key constraints. The solution is disable the foreign keys and delete records with no fear of any errors then enables the constraints again.
Well, I found a solution to disable all constraints without the need to go on each table and disable it manually. and I was happy to know that I can use this solution in deleting all records from all tables. Not only this I was able to use the same solution to reset identity columns in all tables.
The solution was to use this built in stored procedure sp_MSforeachtable. For help about this proc search for it in Books online or use this sp_helptext sp_MSForeachtable.
Now back to my 6 lines, bellow is how I re-zeroed my Database:

   1: /*Disable Constraints & Triggers*/

   2: exec sp_MSforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'

   3: exec sp_MSforeachtable 'ALTER TABLE ? DISABLE TRIGGER ALL'

   4:  

   5: /*Perform delete operation on all table for cleanup*/

   6: exec sp_MSforeachtable 'DELETE ?'

   7:  

   8: /*Enable Constraints & Triggers again*/

   9: exec sp_MSforeachtable 'ALTER TABLE ? CHECK CONSTRAINT ALL'

  10: exec sp_MSforeachtable 'ALTER TABLE ? ENABLE TRIGGER ALL'

  11:  

  12: /*Reset Identity on tables with identity column*/

  13: exec sp_MSforeachtable 'IF OBJECTPROPERTY(OBJECT_ID(''?''), ''TableHasIdentity'') = 1 BEGIN DBCC CHECKIDENT (''?'',RESEED,0) END'