How to set up bike so that back-pedalling stops the rear wheel? My first bike was a 1976 Raleigh Strika. It was brilliant and was distinguished by having only a front brake lever. To get the rear wheel to stop one simply back-pedalled. This was a v. efficient way of stopping and had the bonus of making your bike skid in a most excellent way.

I have a simple 8-speed hybrid mountain/road bike now  and was wondering if anyone knew if there was any way of modding it to replicate the behaviour of my beloved Strika. I guess I might lose my gears after such an alteration, but I can live with that.
This is called a coaster brake. To install one of these, you'd need to replace the rear hub, and remove the existing rear brakes, which sometimes means replacing the rear wheel, and there may be other complications. I recommend retaining your current front brake as a backup; if the chain snaps, you lose your rear brake. (That's happened to me exactly once over the years, and that bike had handbrakes, not a coaster brake.) 

While Shimano makes an internal hub with seven speeds and a coaster brake, I'm not sure if their 8-speed hub has one. 

Can you tell us more about your current bike? Does it currently have gears in an internal hub on the rear wheel, or is the gearing via conventional derailer gears?