Sharepoint - SPSiteDataQuery

public static DataTable GetNames()
{
// retrieve the reference to the site where the Web part is on

SPWeb web = SPContext.Current.Web;

// retrieve all the different types of beers via a CAML query

SPSiteDataQuery qry = new SPSiteDataQuery();

qry.Query = "< OrderBy>
qry.ViewFields = "< FieldRef Name='Type' />";

qry.Lists = "< Lists ServerTemplate='100' />";

qry.Webs = "< Web Scope='Recursive' />";

// -- execute the query

DataTable dt = web.GetSiteData(qry);

return dt;

}