1. A computer-implemented method for improving the efficiency of memory management operations performed on data objects stored in computer memory, the method comprising: selecting a data object; determining a numeric value of an annotation associated with said selected data object, said numeric value being indicative of the likelihood said selected data object would be removed from memory in a garbage collection operation; comparing said numeric value to a predetermined threshold value to determine if said numeric value has a predetermined relationship to said threshold value; if said numeric value has said predetermined relationship to said threshold value, immediately performing a garbage collection operation on said selected data object; and if said garbage collection operation indicates said selected data object may no longer be needed by a program executing on the computer, immediately removing said selected data object from memory.