As students are entering the classroom and preparing for the class, play this song informally. Just let it be the background sound, most of my students know and like this song anyway.
Ask students to watch/listen to this video. The video is of the same song but instrumental only. Ask students to work in groups to write the lyrics of the song from memory. (you can do this activity with any well known song where you can find an instrumental version)
The groups compare their lyrics and then check it against the original version. This is a good listening exercise. If there are still problematic parts of the song, allow students to use the net to resolve them. This will help them develop skills for finding information.
If your students need speaking practice more, have them talk about how they understand the lyrics. If they need reading or writing practice, you can have pairs or small groups do a short research of the net to find how other people interpret the lyrics and then report either orally or in writing on the class blog or on the classroom walls.
There are a lot of interesting interpretations of the lyrics here (but definitely not only here):