While playing around with a Silverlight app, I discovered something that totally fits the bill:

vb Code:
  1. Imports System.Windows.Threading
  2.  
  3. Dim WithEvents timer As DispatchTimer = New DispatchTimer
  4.  
  5. timer.Interval = New Timespan(0,0,1) ' Set the timer's interval
  6.  
  7. Private Sub TimerTick(ByVal sender As Object, ByVal e As System.EventArgs) Handles timer.Tick
  8.    ' Do work here.
  9. End Sub