The ShpToObs plugin is part of the Quantum GIS (QGIS) plugin repositorys. If you want to use it, first, make sure you have a current version of QGIS installed. If so, please find the plugin in the plugins manager. You might have to enable "Show experimental plugins" to be able to get it displaied. Ckeck the checkbox next to "ShpToObs" to instal.
Please notice the manual "index.htm" in the plugins folder.