pyqgis - Can QGIS map canvas update while python script is running?

I want to automate a periodic refresh of the QGIS map canvas with updated shapefiles. A Python plugin or console script does not allow the map to update until the script terminates. Is there a way to force a map refresh in a running plugin or script, or is a stand-alone app required?

Using v1.7.4 now but could migrate to newer version.