Pace and Workout
There are several utilities on the web that attempt to predict race times from a
performance at a different distance. Below are links to several of these.
-Java required -1500 through Marathon -no 1600 or 3200
-Mile, 5k, 10k, 1/2 Marathon and Marathon only
Track and CC Performance, Goal Setting Utility and
World Magazine has a nice collection of calculators.