We change the style of a lot of our covers. Pretty Vacant in a swing style, Groove is in the Heart starts off swing and then at the 1,2,3 bit changes to a fast bluegrass, I Bet That You Look Good On The Dancefloor as a rockabilly song, etc.
The punters seem to really love recognising the song but not really twigging exactly what it is for a little bit, usually when the chorus comes in.
Great fun for all involved and if you get bored playing a crowd pleaser you can keep it in the set but change the style to keep it interesting.
Oh yeah and believe it or not I have woken up in a skip, but I wasn't naked so probably doesn't count, ah alcohol, my dear friend