COMET (or Reverse AJAX) based Grid Control for ASP.NET

http://www.codeproject.com/KB/aspnet/CometGrid.aspx
http://www.codeproject.com/KB/aspnet/CometAsync.aspx

http://www.infosihat.gov.my/artikelHP/bahanrujukan/HEandICT/What%20is%20Push%20Technology.pdf