Pieces of String and Putting Speed

Here's what looks like an effective putting drill to improve your putting speed (from about.com and Neil Wilkins). The method uses three foot pieces of string placed at different intervals on the putting green. You then roll your golf balls so that they stop between the strings. The author mentions the drill taking your mind off of the line and shifting the emphasis to the speed, referring to some golfers as "line-bound". He also quotes Loren Roberts as saying that he feels he can make any putt if he can get down the speed. That's interesting because Stan Utley pretty much believes get the line right and that will get the ball to the cup - get the ball started on the right line, you 'intuitively' know how far to hit it. I'm one of those 'line-bound' golfers so the drill will be an interesting change. Of course, such change does bring challenges of its own, like what am I going to do with the strings when I'm done?

p.s. Guess one wouldn't have to use strings; tees and pocket change could mark the spots. Maybe that is frowned upon because that would bring the 'line' back into play in a very direct fashion.