Teachers often come across dead-time in class - those few minutes of time when your lesson ends early, when you're waiting for something that you need, and so on. During those times teachers need to be ready to pull out an activity from their grab-bag of ideas. Here are a few that you may want to add to your idea list. Picture discussion: Have several interesting pictures ready on transparencies to be able to pull out for a quick discussion. Or try those "spot the difference" pictures, they are good practice for vocabulary.
Create a story together: Each student takes a turn adding to a story. Have a buzzer or bell to signal when it's time to switch to the next person.
Race the clock: Review verb conjugations or help with their memorization by having each student conjugate verbs in pronoun order under a time limit. Increase the concentration by having students say just one word of the verb conjugation. (ich, lebe, du,...)
Pictionary: A student goes to the front of the class and is given a word that the class has to guess through his/her drawings on the board.
Taboo: Just like the board game, students have to guess a word by listening to the speaker describe the word while avoiding certain words associated with it. For example if the speaker had the word der Tannenbaum, he/she may need to describe it without mentioning words such as grün or Wehnachten.
Memorize a song/poem: This is an activity that can be easily continued for another time. Have a short poem or song ready on a poster or flipchart paper. Cover up a few words or phrases at a time as students repeat the poem/song and continue until they've memorized it all.