Online Planetariums and Sky Charts
When its a cloudy night and wrong season to see your favorite star , you might want to quickly look at a computer software's which emulates the sky. The 1st software I had seen back in my college days was CyberSky. Since then it has added so many futures that I can not even imagine. Since then I had never checked this because I got some alternative open source software like Open Universe and Celestia. Both were pretty good but were little but heavy because of their focus on 3D simulation of all the celestial objects.
Later when my interest switched from fun watching planetary animations to serious stargazing and watching clusters and comets I picked up software specialist in in sky-watching like stellarium and Cartes-du-Ceil.
However there are few websites which delivers interactive sky maps right in your browser.
1. worldwidetelescope [Needs Microsoft Silverlight ]
2. Google Sky (Google Earth is better )
4. Sky and Telescope [Java applet]
5. Astro Viewer [Java Applet]
6. sky-map.org [Google Sky like interface]
7.Sky View Cafe [Java applet ]