Hm, first of all your page template has to be inside your current theme folder: /wp-content/themes/current-theme/ or in a similar folder. Check the Codex (Page Templates #File Folders) to make sure your template is in the right folder.
While looking at the Codex also check the Selecting a Page Template section above if you did everything the right way. Your page templates are only visible for pages, so you’ll not find them in the post section or somewhere else.