You can see your packages logging on to Integration services from SQL Server 2005 Management console. You can keep them in file server as well.
Dim execApp As New Microsoft.SqlServer.Dts.Runtime.Application
Dim execPkg As Microsoft.SqlServer.Dts.Runtime.Package
execPkg = execApp.LoadFromSqlServer("Your Package location"","pkgServer", "pkgUser","pkgPassword", Nothing)
execPkg.Variables("Pkgvariable1").Value = varvalue1
execPkg.Variables("Pkgvariable2").Value = varvalue2
execPkg.Execute()
execPkg =
Nothing
Hope this helps.